Heavy Duty Chrome Vanadium Steel Combination Spanner Wrench - 21mm The combination spanners feature the revolutionary and unique ant slip design ASD features a locking groove and unique geometry, to deliver 400% more surface area than a conventional spanner This delivers greater torque to the fastener, significantly reduces the chance of dangerous slipping and allows the job to be completed faster You can be sure spanners are tough enough to stand up to the harshest working environment Rust proof anti-corrosion Metric wrench sizes