Overview
You don't need this or any sighting aid if your shotgun properly fits you and your mount is repeatable. I suppose if all I ever did was wear a tee shirt while hunting my mount would probably be pretty consistent. But the reality is that I don't dress thinking much about my gun mount, (maybe I should), and I rely on visual aids on my shotgun to align my head with the receiver.
Some shotguns offer a mid-bead. The shooter knows that the windage and elevation are correct when the beads are "stacked". But there are two problems with a mid-bead:
Some ribs slope from the receiver to the muzzle to force the shooter to shoot high - maybe a 70/30 pattern or more. Adding a mid-bead without also adding a taller front sight, would cause you to shoot way high.
Can't see brass or painted beads in low-light conditions.
What I did was add a tiny drop of white fingernail polish at the knee of the rib. The drop gives me a reference for centering the bead.
Aids aren't a bad thing, after all we can't all afford custom made stocks and we have to make do with the adjustment range we get from the manufacturer. And we use aids in bow hunting, (pulling against the stop, or finger touching corner of mouth, etc.) and I use a big round brass tack head on my Marlin Guide Gun to the corner of my mouth to know that my head is in the same position every shot.
Anyways, I wanted a front sight that my eye could pick up easily in dim light. I also wanted a sight wouldn't be visible to the entire avian world while I was hunting.
I'm a relatively new wingshooter and I'm not interested games like trap (boooooooorrrrrrrriiiiiiinnnnngggg). I want to optimize my shotgun for hunting.
I went with the 5" long x 2.5mm diameter green. Why? Well, I've some experience with fibre and bowhunting and rifle sights:
Green is in the sweet spot of your eyes receptivity - so it will be easiest to see in very low light, or in the shade.
2.5mm keeps the brightly glowing dot from being overwhelming in your field of view.
5" is enough body fibre to pick up adequate light in low-light conditions.
My Ideal Product
Given that field stocks rarely fit a 6' tall hunter, it becomes imperative that you have some way of quickly aligning your head with the receiver regardless of clothing, body position or body angle. My ideal sighting product would be a glowing pin that you cannot see unless you've got your head in the right position. I haven't seen such a device apart from the red dot sights.
Hype Versus Reality
The late Tom Knapp was one of the best shooters and best voices in the shotgunning industry. The guy made everything look easy and his smooth baritone delivery style was enjoyable to listen too. As with most things, it is easy to project Tom's skill onto an inanimate object, and then believe that possessing that object will make you shoot like Tom.
The Easyhit isn't a super skinny light pipe with a super narrow viewing angle. I.e. the Easyhit won't eliminate parallax error, so you shouldn't be using it by closing one eye. If you do close one eye, you lose depth perception. The viewing angle of the Easyhit is narrow enough that your off eye will not be able to see the glowing dot, and that could be a blessing for those struggling with eye-dominance.
If your shotgun already comes with a fibre sight, then the only improvement Easyhit can offer is a hooded end that hides that glowing dot. If your shotgun lacks a fibre sight, then the Easyhit was cheaper than other products. But be aware that shipping counts, and I got free shipping.
Installation
The Easyhit is designed to stick down onto the rib of your shotgun barrel. The mounting location is in front of the existing front bead. It is a really good idea to have patterned your shotgun ahead of time so that you know how it shot before installing the Easyhit. And then pattern it afterwards.
Harbor Freight sell these little tiny wood clamps for $2, and 1 or two of them would be helpful in compressing the adhesive for a permanent bond.
So far the Easyhit has stayed put, resisting 25*F cold and 90*F hot. I've also dunked it in a mixture of odorless mineral spirits and ATF (my cleaning solution) will no ill effects. It has made it through one full duck season.
Change to POI
With some careful measuring, I determined that the rib on my Franchi Affinity slopes downward .020" from receiver to front bead. Franchi builds in this slope into the rib so that the gun will shoot slightly high. The Easyhit is slightly taller than my stock bead, lowering my POI. You should keep this in mind in your installation.
Difference in height over stock
POI with stock sight 80/20 distribution
POI with Easyhit Installed 50/50 distribution
So What Does It All Mean?
It is important to note that the Easyhit is not an "aiming" device, but rather a "pointing" aid. That might not make much sense to a new shooter, (which I was 12 months ago), but the general idea is that the Easyhit should be thought of as a "I want to mount my gun at the break of dawn and know that my head is aligned even though I've got on this new 2" thick wonder coat from Cabelas that my wife got me for Christmas" device.
I put the sight on my Franchi and proceeded to miss darn near every clay from the 16yd trap line. So I put up the patterning board and discovered that my POI had shifted significantly downward. Armed with this new knowledge I went back to the 16yd line and hit about 15/25 first round, then 23/25 second round. My point here is that my fire control computer between my ears took some retraining even after I visually understood the POI change. I'm old, so maybe your fire control computer will retrain faster, but you shouldn't expect to just slap this sight on and go 25/25 immediately.
They say a picture is worth 1000 words. So I hope the next 5000 helps you.
Moderate light Indoors
From a shaded location looking out at a bright background
Bright sunny day, clear blue sky
Last shooting light pointed into a dark tree
Last shooting light into a clear sky
Is It Worth It?
Yes, because it is well thought out and cheap ($17 from Amazon Prime free shipping). But make sure that you wrap your head around what it is, and isn't.
Yes, I like it because it is a bright visual reference in the periphery of my view of the target and the glowing end isn't visible overhead.
Yes, because it adheres really well if you clamp it a bit to set the adhesive.
Yes if you are one of those who struggles with cross-eye dominance.
Yes, if you are hunting turkey and your shotgun lacks a florescent fibre sight.
No if you don't have the time to practice wingshooting after installation, because you think it is a magic shotgun sight.