We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-23 · 8 min read · Independent comparison
If you want to keep the earbuds you already own but make them fit, seal and stay put better, choose AZLA SednaEarfit Crystal; if you need a complete set of wireless earbuds with a charging case, gaming mode and long battery life, choose Midcomsys Air 31.
These two products sit in completely different parts of the earbud world, and that is the first thing to understand before you compare them. One is a set of replacement silicone tips designed to upgrade earbuds you already have. The other is a full pair of true wireless earbuds with their own drivers, battery and case. If you landed here expecting a straight head-to-head between two identical categories, this is the moment to reset your expectations — and the moment the choice actually gets easy.
• AZLA SednaEarfit Crystal — biggest strength: premium hypoallergenic German LSR silicone with a naturally grippy surface, an ultra-short 4 mm core, and multiple sizes built from analyzing the shape of more than 1,500 ears.
• AZLA SednaEarfit Crystal — biggest trade-off: it is not an earbud. It is a tip. If you do not already own compatible earbuds, this product does nothing for you on its own.
• Midcomsys Air 31 — biggest strength: a complete TWS package — Bluetooth 5.3, up to 24 hours of playback with the charging case, Type-C fast charging, active noise cancellation, touch controls and a low-latency gaming mode.
• Midcomsys Air 31 — biggest trade-off: it is a closed system. You get the sound the built-in dynamic driver delivers, with no way to reshape the fit or the tuning the way a tip swap can.
• Who AZLA SednaEarfit Crystal is for: owners of compatible wireless earbuds (Beats Powerbeats Pro and Powerbeats Pro 2, Galaxy Buds 2, Buds and Buds+) chasing comfort, grip and better isolation.
• Who Midcomsys Air 31 is for: anyone who needs working wireless earbuds out of the box, especially gamers and call-heavy users.
The SednaEarfit Crystal is a replacement earbud tip, and it is honest about that. What it does best is solve the problem almost every wireless earbud owner runs into eventually: the stock tips that came in the box either leak, slip, or start to ache after an hour. AZLA builds these from German LSR silicone — a liquid silicone rubber — and describes it as hypoallergenic, which matters if your ears react to cheaper rubber tips. The material also has a naturally sticky, grippy surface, so the tip holds its position instead of slowly working its way loose mid-workout.
The second thing it does well is isolate. The design is meant to create an effective acoustic seal, which improves passive noise blocking without recoloring the sound of your earbuds. That is a meaningful distinction: you are not buying a new sound signature, you are buying a better seal around the one you already have. The ultra-short 4 mm eartip core length is the key spec here, because it is what lets these fit a wide range of TWS earbuds without blocking the charging case. AZLA also leaned on a large fit study — over 1,500 ears analyzed across two years — to build out its size range, and sizes span from SS and SSS up through MS and ML.
Who should skip it? Anyone who does not already own a compatible pair of earbuds. And one critical check: AZLA explicitly states these are not compatible with Galaxy Buds Pro, Galaxy Buds Live or AirPods Pro, and the description also flags Galaxy Buds Pro as a no-go. If your earbuds are on that list, this product is not for you regardless of how good the specs look.
Midcomsys Air 31: Who It's For
The Air 31 is the opposite kind of purchase: everything you need is in the box — earbuds, charging case and a Type-C cable. Midcomsys positions it around two audiences, and the spec sheet backs that up. For gamers, there is a dedicated ultra-low latency gaming mode, which is the feature that separates it from a generic budget earbud. For everyone else, there is a dynamic driver tuned for deep bass and clear highs, Bluetooth 5.3 for stable pairing, and an HD noise-reduction microphone for calls and in-game chat.
The practical numbers are the real story. Midcomsys rates playback at up to 24 hours with the charging case, and a full charge takes about an hour over Type-C. That combination — a one-hour top-up and a 24-hour figure — makes it a sensible travel and commute companion, because you are not babysitting the case all day. Bluetooth 5.3 also means the connection should hold up better in crowded wireless environments than older Bluetooth versions, and pairing is described as instant.
Who should buy it? Someone who needs earbuds now and wants one purchase to cover music, calls and gaming. Teens and adults are the stated age range, and the low-latency mode plus mic make it a reasonable pick for casual competitive gaming and voice chat. Who should skip it? Anyone who already loves their current earbuds and only wants a fit fix — that is the AZLA's job, not this one's. Also skip it if you specifically need replaceable, tunable tips, because the Air 31 does not offer that path.
Side-by-Side: Which Should You Choose?
• Best for upgrading earbuds you already own → AZLA SednaEarfit Crystal. It changes fit, grip and isolation, not your hardware.
• Best for a complete out-of-the-box solution → Midcomsys Air 31. Earbuds, case and cable are all included.
• Best for battery life → Midcomsys Air 31. Up to 24 hours of playback with the charging case, with roughly a one-hour charge time.
• Best for sensitive ears and long sessions → AZLA SednaEarfit Crystal. Hypoallergenic German LSR silicone is the whole point of the product.
• Best for workouts and running → AZLA SednaEarfit Crystal, assuming your earbuds are compatible — the naturally grippy surface is designed to resist slipping.
• Best for gaming → Midcomsys Air 31. The ultra-low latency gaming mode is a feature the AZLA simply cannot offer.
• Best for calls → Midcomsys Air 31. It has a built-in HD noise-reduction microphone; a set of tips has no microphone at all.
• Best for Beats Powerbeats Pro owners → AZLA SednaEarfit Crystal. It is explicitly built with Powerbeats Pro and Powerbeats Pro 2 in mind.
• Best for Galaxy Buds Pro, Buds Live or AirPods Pro owners → Midcomsys Air 31, because AZLA states its tips are not compatible with those models.
In my opinion, these two products do not compete — they answer different questions, so the honest recommendation depends on what you already own. If you have compatible earbuds and your only real complaint is that they slip, leak or hurt, I would buy the AZLA SednaEarfit Crystal. It is the cheaper-feeling fix in spirit: you keep the sound you like and change the part that is letting you down. If you do not own wireless earbuds at all, or you want gaming mode, a mic and a 24-hour case in one purchase, I would buy the Midcomsys Air 31. For most readers who arrived here looking for actual earbuds rather than tips, the Air 31 is the one that stands on its own. Check the current price on Amazon before you decide, since that is the one variable this comparison deliberately leaves out.
how to tws earbuds
TWS stands for "true wireless stereo," meaning the two earbuds connect to your device independently with no wire between them. With the Midcomsys Air 31, that connection runs over Bluetooth 5.3. The AZLA SednaEarfit Crystal is not a TWS device — it is a set of tips for TWS earbuds you already own.
how to pair tws earbuds
Take the earbuds out of the charging case and they should enter pairing mode, then select them from your phone's Bluetooth list. The Air 31 uses Bluetooth 5.3, which Midcomsys describes as offering instant pairing and a strong, reliable connection. If pairing stalls, put both earbuds back in the case and start again.
how to reset tws earbuds
A reset usually means clearing the earbuds' stored pairing memory so they can connect fresh. The exact button combination varies by model, so follow the instructions that come with your specific earbuds — the Air 31 ships with a charging case, earbuds and a Type-C cable, and its manual is the authority on its reset sequence. There is no reset procedure for the AZLA tips, since they contain no electronics.
how to connect tws earbuds
Connecting is the same as pairing: enable Bluetooth on your phone or laptop, open the case, and choose the earbuds from the available devices list. The Air 31's Bluetooth 5.3 radio is designed to hold that link reliably once established. If you use the AZLA SednaEarfit Crystal, you are not connecting anything new — you are simply swapping the tips on earbuds that are already paired.
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