This is the M1 from Mastery Bridge, a well-known high-performance bridge that can be installed on guitars such as Jazzmasters, Jaguars, and Mustangs. I purchased it and tried it out, but I am selling it due to reorganizing my equipment. Since it was only used for testing, it is in almost new condition. It will be shipped in the original drawstring bag and aluminum case. #guitar #bass #masterybridge #jazzmaster #jaguar #mustang #fender