SWIVEL BASE FOR MILLING MACHINE VISE. Condition is "Used". PIVOT PIN 1 3/4, 3/4 TSLOT, OUTSIDE TO OUTSIDE 8 1/8, INSIDE TO INSIDE 6 15/16 , MOUNT HOLE 13/16, 5/8 KEY IN BOTTOM. I HAVE OTHER SWIVEL BASES IF YOU NEED DIFFERENT SIZES SELLING AS IS CHECK OUT PICTURES