ProMag Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine Blued 1 Pack Steel RUG 24-10RD. Those made of steel are then tig welded for strength. The springs are precision wound using heat-treated chrome silicon wire. Bases & followers are injection molded from polymers selected for their durability. What do we mean when we say "ProMag dependability"? Quite simply our products are able to withstand years of constant use and still be able to perform without the slightest hint of difficulty. Each and every step of the assembly process is checked and double checked in order to maintain the same consistent level of quality. Specifications for ProMag Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine: Manufacturer: ProMag Gun Make: Ruger Gun Model: Ruger Mark III 22/45 Caliber: .22 Long Rifle Magazine Capacity: 10 Round Color: Blued Fabric/Material: Polymer Package Contents: ProMag Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine What firearm models does the manufacturer say ProMag Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine is compatible with? The manufacturer says that ProMag Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine is compatible with Ruger Mark III 22/45ProMag RUG 24-10RD: Ruger Mark III 22/45 10 Round .22 LR Pistol Magazine Blued 1 Pack Steel