CATERPILLAR, 4522740 Thumb, UTILITY HYD THUMB, 12" WIDE, NO LINK STYLE, (2)TEETH, STICK MOUNTED, BRACKET IS ALREADY ON MACHINE, *NO RELIEF VALVE*REQUIRES TWO WAY AUX LINES GROUPTEETH WILL MESH WITH 16", 18", AND 30" BUCKETS ONLYFOR USE WITH: MACHINES WITH S/N BXT00447 AND UP, Attachment, Serial Number: A4169TH20128