Products included are: 1x MP5 Buffer This MP5 buffer is intended for full-size MP5 builds, where a buffer is required as part of the setup. Full-size MP5 builds require one of our MP5 buffers. MP5K builds do not need a buffer. Over time, buffers can harden, discolor, or crack, which may affect function. Replacing a worn buffer helps maintain consistent operation and keeps the build aligned with platform requirements.