Our BX-1 10/22 Magazine Base Plates are cnc machined form 6061-T6 aluminum and is designed to fit all Ruger 10/22 10 round BX-1 magazines. The base plate installs without the use of glue or tape and does not require drilling and tapping. Installation is easy and takes only seconds. Each base plate weights 42 grams (1.5oz) which helps the BX-1 magazine to easily drop free from the rifle.