This is an NOS frame mounted rear axle brake line tee. This is an original WWII surplus item. These were for the GMC CCKW which was the 2 1/2 ton truck or Duce and a half. This talks the rubber brake hose and then splits off into two brake lines. This was frame mounted. This is solid brass US Made construction and has a metal attachment tab. This fits and can easily made to work with other vehicles as well.