Inside the Waistband IWB Concealed Gun Holster for Beretta Px4 Storm Compact and Subcompact and BU9 Nano Gun holster for concealed carry fit for subcompact semi-auto pistols. Inside the waistband carry method. Material is high quality synthetic suede that is very smooth & will not irritate the skin like other holsters. King Holsters are by far the best bet for maximum concealed, comfortable carry. Listed below are examples of guns that will fit this model holster. Please note this list is not intended to be all inclusive. More guns will fit this holster.