(Note: Measurements are outside max. dimensions unless stated otherwise).18th Century : Castor collar.External rim diam. 39mm. (1 9/16")Internal rim diam. 35.5mm. (1 3/8")Depth 18mm. (11/16")Depth of top rebate to ledge 12mm. (7/16")Depth of underside rebate to ledge 4mm. (3/16")Height 17mm. (5/8")External bead with internal ledge.An end of leg capping in which the flat plate of a plate castor fits giving an elegant decorative finish to the leg.