The CRL Persuader Urethane Chisel was designed by a glazier for use in cutting the bottom urethane seal on windshields from the inside. On most cars the top and sides are cut out with a cold knife. The lower corners can be cut using the CRL Persuader Urethane Chisel which usually frees the windshield enough so it can be tilted out from the top and the balance of the urethane can be cut with a utility knife.