The firearm is held fast by a retention strap (thumb break), and a traditional tension screw device.
Size 71 Fits G17192223 MP40 XD40 Sigma9
Size 73 Fits Be92F96
Size 77 Fits Co 1911 B-HI-Power
Size 79 Fits KL4
Having been in law enforcement for over 30 years, I was delighted to find a holster with a simple thumb break system. Looks better than leather and very durable. Very pleased with this product.