The KWA LM4D/F90/Radian MOD.1 GBB Hop Rubber is a genuine replacement part designed for compatible KWA gas blowback rifles. If you are maintaining an LM4D, F90 or Radian MOD.1, this is the correct hop rubber to use when refreshing the hop and barrel assembly with the proper factory-spec component.
A worn hop rubber can affect how consistently the rifle applies hop to the BB, which in turn can make the gun feel less predictable shot to shot. Replacing it with the right KWA part is a practical way to keep your rifle shooting as intended and avoid guesswork during a rebuild or repair.
This item is listed under KWA part numbers 3039 and 1508, which helps when matching parts during servicing. For experienced techs and regular GBB users, having the correct hop/barrel component saves time and keeps maintenance straightforward.
You may also want to check related KWA hop/barrel parts or GBB internal parts if you are completing a wider service. Order the correct KWA hop rubber today and keep your build moving.


