Tomo of PDI/X-Fire just sent in the latest news coming from their company and this one's a front barrel set for the TM VSR-10... "You can do custom same size as "VSR-10 G-SPEC" with PDI Bull Barrel Base and this Front Bull Barrel. Please use with PDI Bull Barrel Base. This is made of Duralmin, with Black Anodization. The outer diameter (Front and Rear)is 30.5mm(G-SPEC size), comes with  O-ring, and has an overall thickness of 6mm."