Check the listing for details. Belt Grinder Tracking Wheel for 2x72" knife making grinder 4" diameter. Condition: New. Listed at 16.95 USD. Precision glass filled nylon tracking wheel with sealed bearings for DIY style 2x72 grinders like GIB, EERF, NO WELD etc. Also work well on any professionally manufactured 2x72" belt grinder. We designed these wheels with weight in mind, they really zip & will give your grinder extra help if you started off with a slightly underpowered motor. Made with the exact same injection molding technology & material as used on modern automotive engine serpentine belt idler wheels for extreme durability & longevity under very harsh conditions. The wheel is 4" in diameter & crowned to ensure accurate belt tracking.We make our wheels 2-1/4" wide to accept any commercial 2" grinding belt. Includes sealed bearings which can easily be replaced when worn. Bore of the bearings is 1/2" so you can use any 1/2" diameter bolt as an axle. We use these wheels in our top quality grinders & have tested them extensively. Please also have a look at our other listings & search OriginBladeMaker on Youtube for some other fun stuff.