Aviation spark plugs have special needs; using a non-standard 7/8" hex, and exhaust manifolds can get in the way of wrench access. A thin-wall socket is necessary for many applications. To ensure compatibility with all makes of plugs including Champion and Tempest, a deep well is called for. This Aviation Spark Plug Socket meets all these needs, with a combo hex and 3/8" drive for additional flexibility. Pro-quality.