Small steel balls used in the moving parts of machinery and vehicle wheels. Scattered on a level floor, they roll beneath the feet and can bring a pursuer down. Unlike caltrops, they obstruct movement without relying on sharp points.
Small steel balls used in the moving parts of machinery and vehicle wheels. Scattered on a level floor, they roll beneath the feet and can bring a pursuer down. Unlike caltrops, they obstruct movement without relying on sharp points.