THIS IS A NEW OLD STOCK WILTON SWIVEL BASE. THE PART NUMBER IS 101089. IT WAS ORIGINALLY BOUGHT FOR A 4 INCH WILTON MECHANICS VISE BUT NEVER USED. THE VISE IT WAS BOUGHT FOR HAD A CASTING NUMBER OF 111055 ON THE MAIN BODY AND 111056 ON THE REMOVABLE JAW. THE INNER DIAMETER OF THE BASE IS 5 INCHES AND THE RING THE VISE WOULD SIT ON IS 3/8 INCH WIDE. THE BASE HAS BEEN CLEANED AND A NEW COAT OF GRAY PRIMER APPLIED. THANKS FOR LOOKING.