These "5 Star Firearms" brand speed loaders are made from 6061 billet aircraft aluminum. They have delrin core bushings to ensure a smooth twist of the key every time. Our assembly hardware is made from high quality stainless steel pins, wire springs, and precision ground bearings. Each speed loader is hand assembled and hand tested to ensure 100% quality approval. All of the main components are manufactured in house using over twenty state of the art CNC machines. You may notice that some of these speed loaders have a solid top. This is because some cylinders are spaced too close together making the internal walls too thin to machine. A solid top allows us to manufacture speed loaders their competitors don’t. All of their speed loaders use a simple twist of the hex key to lock or release your rounds into the cylinder. This "5 Star Firearms" speedloader is designed for the S&W 36. 37, 38, 40, 42, 49, 60, 340, 360, Charter Arms 85, 608, 651, 851, and The Taurus 85, 605, 651, 851 and Rossi 68 and Ruger SP101. This is designed for this pistol and fits much better than the HKS version which is a catch all. These aluminum speedloaders are certainly top of the line and well worth the extra money.