The Orvis PosiGrip Screw In Studs add traction to the soles of your favorite wading boots in moments. These studs feature aggressive tungsten carbide tips that can be added to any wading boot with at least 1/2'' of midsole depth. The sharp tip allows for quick and easy installation into felt or rubber outsoles. These studs are a must where maximum traction is needed. 1/4'' hex head screws. Adapter for power drill included. 24 studs per pack.