This is the McCoy MC-8 Glow Plug.
FEATURES: Medium to Cold heat range For nitro fueled cars or boats Heated by 1.5V source Silver/chrome colored with 5/16" size hex INCLUDES: One MC-8 Glow Plug One Copper Washer REQUIRES: Glow Igniter (GPMP2012) and Wrench (HCAP2550) COMMENTS: This is a standard long plug (no idle bar).