up for sale is a brand newmagnetic lock out keywill fits for U.F.P type surge brakeactuators include A-60,A-70,A-75, A-84 Replaces silver factory keys prefectly(part number is 34557) Recommended Scenarios backyour trailer up to boat yard maneuveryour  trailer into or out of a parkingspot tryto back your trailer up a hillProhibited Scenarios(WARNING) USE AT YOUR OWN RISK, when you towing your trailer forward on road,do must removedthe "MAGNETIC LOCK OUT KEY",because when you using the key,brakingaction inhibited,it's very deanger without protection of brake. wishyou a happy shopping!!!