The Aker Leather 514 SMP single magazine pouch is a staple of any concealed carry belt set up. Leather magazine pouches wear to the user over time becoming increasingly comfortable over years of use. Constructed from the highest grade of vegetable tanned leather, the SMP features our proprietary extra strength "quick-on" heavy duty metal spring clip. On the rear of the clip, there is a small barb that hooks underneath your belt so that it does not slide around. The unique passive retention device on the inside always keeps the magazine secure in the pouch. Many departments, including the LAPD, provide this magazine pouch to their detectives and off duty officers, however, it also among our best seling for EDC and shooting sports enthusiasts. Size 1 fits one single stack .45 ACP magazines, such as for most 1911's and the Sig Sauer P220. Size 2 fits one double stack 9mm magazine, such as for the Beretta 92 and Sig Sauer P229. Size 3 fits one double stack 9mm/.40 caliber magazine, such as for the Glock 17 and Smith & Wesson M&P 9 and 40. Size 4 fits one double stack .45 ACP magazines, such as for the Glock 21 and the HK 45.