Called "box spurs" because the inter-projections snapped into a small steel box mounted in a cavity in the rear of the boot. Inside was a spring-loaded catch. Most of these spurs were European imports and were quite popular. This pair is in excellent condition. The top of each projection is stamped LEFT or RIGHT and BEALS LONDON on the bottom. This particular spur was designed to look like it has been screwed to the boot when attached.