Ronix 167630: Buy Ronix Eight.3 Wake Surf 2 Inch Boat Shim.,.Ronix. Manufacturer Part Number. 167630. Manufacturer. Ronix. Color. White. Warranty.Ronix Eight.3 2 Inch Boat Shim With a 2″ shim The shims are used on some hull designs due to the steps on the hull. Since each boat model is different you may not need to use all or any of the shims.