Compatible with ColdSteel PROFESSIONAL MODEL ONLY 2.5 mm Wall Finally a comfortable way to shoot your blowgun and increase performance. Perfect for all size hands, ensures a solid grip to help steady your aim. Great on warm days when your hands sweets or those frigid days when using your gloves to get that extra grip. Compatible with Cold Steel Magnum Blowgun & Venom Blowguns .625 Hunter Series, This will not fit Cold Steel MAGNUM or any blowguns with 1.5 mm walls, Made in USA with environmentally save process's with EPA guidelines, no CFC's Used !!!! To attach to any 2.5 mm wall .625 blowgun you simply slide the grip over the tube, using water to wet the tube slightly or baby powder helps make this easier.