This is used to remove canister type screw on oil filters from cars, vans etc. It has a strong flexible nylon woven strap that can fit around filters up to 120mm in diameter. Can be used with a 1/2" square drive accessory or 13/16" AF open end spanner. Using a 1/2" square drive extension bar, together with a ratchet, allows access to the most awkwardly sited filters.