VFC MP5 Hopup Arm and Nub V2 vipertech -Cutout for tension O rings

-Cutout for tension O rings specifically for open bolt guns such as the VFC M249

To give you potentially essential information I measure each catch several times and write down the exact height of the catch surface on packaging

The height may need slight adjustment to get the correct height

I would encourage you to complete this piston by buying Bavtechs Brass piston to complete this

VFC MP5 Hopup Arm and Nub V2 vipertech -Cutout for tension O ringsThis arm provides more consistent hopup tension on the bucking for more consistent BB backspin. 7075 anodized aluminum. Rubber Nub. This new version is CNC machined rather than 3d printed. This hopup arm allows for the use of a rubber nub which will greatly improve your hopup consistency!