here the thing my uncle made me 10 years ago thats on my hunting gun scared to take it off much scared i might break it or mess it up by takeing it off to put on a diff gun its made out of aluminum my uncle made it at a place he did work but that place has closed down its about 3 to 4 inch long it has a small allen screw in it to tighting it down and im scared if i take it off much it might mess the threads up