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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want marathon battery life and an over-ear design you can fold away in a bag, choose Picun B8; if you need a featherweight open-ear clip that stays put through sweat and rain, choose Monster Open Ear AC339. Both are wireless, both lean on touch control as their main way of getting things done, and both sit in the same mental shopping list for most people. The real split comes down to how you wear them and what you ask them to survive.
• Picun B8 biggest strength: 120 hours of playback from a 1000mAh battery, plus multipoint connection and a 3.5mm wired fallback when you run out of juice.
• Picun B8 biggest trade-off: It's a full over-ear headphone, so it's bulkier, warmer on the ears, and has no water-resistance rating to lean on.
• Monster Open Ear AC339 biggest strength: An open-ear clip design with IPX6 water resistance, Bluetooth 6.0, and a 40-hour battery with a digital display so you never guess the charge level.
• Monster Open Ear AC339 biggest trade-off: Open-ear means no sound isolation at all, and the 40-hour figure is roughly a third of what the Picun offers.
• Who Picun B8 is for: Commuters, students, office workers, and anyone who wants one pair for long listening sessions and hands-free calls.
• Who Monster Open Ear AC339 is for: Runners, gym-goers, and cyclists who want to hear traffic and their surroundings while staying connected.
The Picun B8 is built around one idea: keep the music going for as long as humanly possible. The 1000mAh battery is rated for more than 120 hours of playback on a single charge — enough that the brand frames it as "30 days without charging" if you listen four hours a day. That's not a marketing number you can ignore; it changes how you use the product. You stop thinking about charging cables, and that matters for travel, long study sessions, and anyone who has ever landed at an airport with dead headphones.
Under the hood you get dual 40mm dynamic drivers, a 32-ohm impedance, and a 20Hz–20kHz frequency range. There are three EQ modes — Pop, Bass Boost, and Rock — cycled by pressing the EQ button twice. It's a simple, physical-first system that doesn't ask you to open an app. Bluetooth 5.3 handles the connection with a stated range of up to 10 meters, and there's a low-latency mode you toggle by pressing the power button three times, which is the kind of detail that matters if you watch video or game on the same pair.
Who should buy it: Anyone who prioritizes battery life, wants over-ear comfort for long sessions, and needs one pair that handles calls, movies, and music without babysitting a charger.
Who should skip it: If you run, lift, or ride in the rain, this isn't the tool. There's no IP rating listed, the over-ear fit traps heat, and 120 hours of battery doesn't help you if sweat is the problem.
Monster Open Ear AC339: Who It's For
The Monster Open Ear AC339 goes the opposite direction: minimal weight, maximum awareness. The clamp-over open-ear design sits outside your ear canal rather than sealing it, which is why the brand leans on comfort and a snug fit without added pressure. If you've ever pulled sealed earbuds out mid-run because they felt like pressure plugs, this is the design that solves that specific complaint.
The spec sheet backs up the athletic positioning. IPX6 water resistance means it shrugs off strong jets of water from any direction — sweat, rain, and post-workout rinse included. Bluetooth 6.0 is the newer wireless standard here, and the battery is rated at 40 hours with a smart digital display that shows your remaining charge in real time. That display is a genuinely useful touch: no guessing, no blinking-light interpretation games.
Touch control is the whole interface. A single touch handles answering and hanging up calls, the voice assistant, music control, and other functions. The brand explicitly frames this around driving, exercising, and running — situations where you don't want to fumble for a button. The drivers are dynamic with a 20Hz–20kHz frequency range, matching the Picun on paper, and the enclosure is silicone in beige. One thing to note: the listing describes the control function as "simple button control" in one line while the control method field reads Touch — the practical takeaway is that a tap does the work.
Who should buy it: Runners, cyclists, gym regulars, and anyone who needs to hear their surroundings for safety or just prefers not to seal off the world.
Who should skip it: If you fly, commute on noisy trains, or work in an open office, open-ear means zero isolation. You'll hear everything around you, and so will everyone near you at higher volumes.
Side-by-Side: Which Should You Choose?
• Best for workouts and wet weather → Monster Open Ear AC339. IPX6 is the deciding factor; the Picun has no listed water resistance.
• Best for sound isolation → Picun B8. Over-ear PU leather cushions block outside noise by design. The Monster's noise control field literally reads "None."
• Best for situational awareness → Monster Open Ear AC339. Open-ear clips leave your ear canal open, which is the point if you run near traffic.
• Best for wired backup → Picun B8. It ships with a 3.5mm audio cable and a 3.5mm jack. The Monster has no jack at all.
• Best for charge-level clarity → Monster Open Ear AC339. The digital display shows remaining battery in real time; the Picun relies on iOS battery readout and its own indicator.
• Best for multipoint and calls → Picun B8. Multipoint connection and a built-in microphone make it the stronger pick for switching between laptop and phone.
• Best for newer Bluetooth → Monster Open Ear AC339. Bluetooth 6.0 versus Bluetooth 5.3, which is a generation ahead on the wireless spec.
• Best for hot, long sessions → Monster Open Ear AC339. Open-ear and silicone won't trap heat the way over-ear faux leather does.
In my opinion, the Picun B8 is the better buy for most people, because 120 hours of battery, multipoint connection, over-ear comfort, and a wired fallback cover more of daily life than any single open-ear advantage does. I'd recommend the Monster Open Ear AC339 without hesitation to a runner, cyclist, or gym regular — the IPX6 rating and open design are exactly what that person needs and the Picun can't match. But if you're buying one pair to do everything else, the Picun B8 wins on sheer staying power. Check the current price on Amazon before you decide, since that's the one variable worth confirming for yourself.
how to disable touch controls on headphones
There's no universal switch, because touch control is baked into each model's firmware rather than exposed as a setting. On the Picun B8 you can lean on the physical buttons for many functions, but the touch gestures for calls and the voice assistant are part of the control scheme. On the Monster Open Ear AC339, touch is the primary interface, so disabling it would leave you with very little control. If a stray tap is bothering you, the practical fix on most headphones is to check the companion app, if one exists, or to keep the earbuds away from loose fabric.
why are my headphones controlling my phone
This is normal behavior, not a malfunction. Both the Picun B8 and the Monster Open Ear AC339 are designed to send commands to your phone — a short touch answers a call, three short touches wake the voice assistant, and taps manage playback. That's the whole point of touch control: it lets you run your phone without taking it out of your pocket. If it's happening when you don't want it, it usually means the earbuds are still connected and picking up accidental taps.
what is touch control on headphones
Touch control means you operate the headphones by tapping or holding a touch-sensitive panel instead of pressing a physical button. On the Picun B8, a short touch answers a call and a three-second touch rejects one, with physical buttons handling volume and EQ. On the Monster Open Ear AC339, a single touch covers calls, the voice assistant, music, and other functions. It's faster and more weather-friendly than buttons, but it also means accidental taps are a real possibility.
are open ear earbuds better than over ear headphones
Neither is better — they solve different problems. The Monster Open Ear AC339 keeps your ear canal open, which is safer for running and cycling and more comfortable in heat, but it offers no noise isolation. The Picun B8 is over-ear with PU leather cushions, which blocks outside sound and suits long listening sessions, but it's bulkier and has no water-resistance rating. Pick based on whether you want to hear the world or shut it out.
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