The BX-1 is the Ruger factory ten round .22LR magazine for the 10/22 family of rifles.
Manufactured from a hard wearing black plastic.
Ruger’s compact and reliable rotary magazine design is the main reason why the Ruger 10/22 is the world’s most popular rimfire rifle, with a whole industry of aftermarket parts based around one magazine.
You can’t go wrong with having extra magazines, whether it’s for fast loading at the range or in the field. Or, as a backup in case of loss, damage or muddy puddle encounters