This is a top quality, heavy weight cast brass whole roller buckle, made to fit a strap width of 16mm (5/8")
These are very strong buckles, ideal for use on dog collars and horse tack.
Internal width: 17.6mm
External width: 24mm
Total external length: 37mm (1 1/2")
A 'whole' buckle means that it has a bar across that holds the end of the strap down, rather than needing a separate loop of leather or metal after the buckle.