Wahl Bros Racing No Slip Drive Sockets - 3.0in. Pitch - 7T - 1 1/16in. - 1 1/8in. Hex 02-587A Specifically designed for less rotating mass Built to drive off of four track lugs and track clips at the same time Extra involutes are eliminated with these sprockets Sold in pairs Some models will require the front of the slide rails be shortened for clearance.