This is a Sig Sauer Magazine chambered in 22 LR, model MAG-226-22-10.
Trusted by military" police and civilians for decades" SIG SAUER has earned a worldwide reputation for the unquestioned accuracy and unflinching reliability of its pistols and rifles. SIG SAUER magazines provide exceptional fit and reliable feeding in their high quality firearms.
Sig OEM Magazine
Fits Sig P226 in .22LR