This is a Mastery Bridge M1, compatible with Jaguar, Jazzmaster, and Mustang guitars. It's an M1 (with bridge post diameter of 0.310 inches (7.874mm)) that fits Fender USA models. While it's technically possible to use the M1 on guitars with metric-sized posts like Fender Japan models (which are only about 0.1mm larger), it's recommended to use the metric-sized post (M2/8.001mm) separately. It's in good condition, but it has been used, so there may be minor scratches. Please check the photos.