Case comes with an internal tensioning device to retain magazine in place Fits double stack 9mm or .40 caliber metal or polymer magazines Accommodates belt widths from 1 to 1 3/4 This polymer magazine case comes with an internal tensioning device to retain magazine in place. Accommodates belt widths from 1 to 1-3/4. Fits double stack 9mm or .40 caliber metal or polymer magazines.table.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; }