Ride on trencher parts for all major brands from Ditch Witch to Vermeer and Case, Drive Sprockets, Auger Sprockets, End Rollers, Bare Chain, Configured Chain, Welded Shark to Cup Chains, chain teeth, bearings, idler shafts.PITCH IS THE CENTER TO CENTER MEASUREMENT OF THE CHAIN PINS NUMBER OF LINKS ON A CHAIN IS THE NUMBER OF CHAIN PINS DIVIDED BY 2