The Universal Inside the Waistband Series Holsters are designed to accommodate multiple same-sized pistols. The IWBL is for large frame pistols, the IWBM is for medium frame pistols and the IWBS is for small frame pistols. Place the holster inside your pants all the way down until the two belt clips completely encircle your belt. The location of the holster around your waist is based upon personal preference. Retention is achieved by pressure from the user's belt applied to the holster shell when worn on the body. The unique flexible backing conforms to the user's body allowing for additional retention. The non-slip surface of the holster backing keeps the holster firmly in place. The Universal IWB Series holsters are designed for many pistols and DO NOT have a standard passive retention mechanism.