I deal with V-style/fanged hopup buckings, so type B was the one for me. However, seeing as I already use fanged buckings, I didn't really need to buy this, as the intended purpose of keeping your bbs on-center through the hopup chamber was already achieved with the fanged bucking
Type A: fanged lever centers the bb as it passes through a flat bucking (that's been turned "fanged, per-say by the lever."
Type B: flat lever pushes down on the fanged bucking, simply using the fangs as they should.
That being said, Type-A is an upgrade for those of you with traditional flat-style buckings. However, this one: Type-B, is more of an accessory, though I use that in the best way possible. It's always better to have metal parts in your gun, and unless you've got relatives in a machine shop somewhere, you can't beat the price.
Definitely more durable than the stock one, which is cheap plastic.
This is a drop-in piece, little to no modifications required.
Not really necessary if you're already using fanged buckings.
Rating: [5 of 5 Stars!]