Extra Security. With the high price of gas these days it is no wonder locking gas caps have become popular again. Stop thieves from siphoning the gas from your tank (or an ex from adding something extra to your tank) with a RedRock Locking Gas Cap.Application. This RedRock Locking Gas Cap is designed to fit 1987-2023 Wrangler YJ, TJ, JK and JL models. This locking fuel cap comes with two keys.