This weaver rail by Rap4 will make an older Model 98 Custom have a rail system similar in function to the newer Platinum edition guns. The rail covers the entire top of the gun and has a 6 inch Weaver/Picatiny rail. The rail is made of sturdy aluminum, anodized black. This is held in place with 6 set screws using the included allen key to tighten them down. Instalation can be done with easy by any user.