The revolutionary rollers are of high quality synthetic materials providing a tough and robust composition that is to withstand even the toughest use. The roller has been designed to accept rubber bands of most dimensions including 18.5mm. The removable hydro plugs have pre-installed spacers which help greatly with the right placement of the rollers on the speargun head of any construction.The upgrade kit, that is sold separately, offers stainless steel ball bearings that are of very high quality. The ball bearings can withstand extremely large loads while maintaining a perfectly smooth function. A great point to be mentioned is that the stainless steel bearings can be places on a threaded 6mm axel without sacrificing function longevity.The Rollers can function with any setup one desires. Either with hydro lubricated plugs (standard), one ball bearing and one plug per roller (for lighter head weight) or by installing full ball bearing kits for large loads.The roller head dimensions are:Width: 17mm, Outer diameter: 7.5mm, Inner diameter: 21mm.

The Stainless Steel ball bearings:Axel diameter opening: 6mm

Listing is for a single roller.