There may be no more easy concealment than appendix carrying a slim subcompact pistol, like a Sig P938 in a Sig P938 AIWB holster. But does that necessarily mean any one holster of that type is going to get things right. Many P938 appendix carry holsters are easy concealing. They aren't always very adjustable, though. Not many are actually all that comfortable. The backer. is made of layers of closed-cell neoprene, a spring steel core, and our proprietary Alien Skin surface material. This puts a cushion against the wearer that also repels moisture. The spring steel ensures stability and security, but also comfort as it flexes to conform to your shape and keeps you from feeling your gun through the fabric. The Alien Skin helps hold a holstered pistol but doesn't touch the finish. The shell is custom-molded for the Sig Sauer P938 with a proprietary durable polymer, virtually indestructible under normal conditions of use. The fit will be perfect right out of the box, with no break-in time needed. This holster comes ready to go. The retention is also adjustable, as you can set the passive retention to the setting you desire. The ShapeShift is certainly a sign of intelligent holster life.