My BLX 6.1 95 came with an annoying rattle in the handle with off-center contact. I removed the butt cap cover, and it stopped. I switched out the cover with one from another racquet without luck. My search in this forum found a solution of keeping the cover (or trap door) off, which I didn't want to do. I tried a tiny strip of duct tape, placed it on the edge of the inside of the handle, and replaced the cover. That was the answer to a loose trap door.