L2D Combat Guide Rod Reducing Ring Glock Gen 3-4 Titanium Nitride. When used in conjunction with an L2D Combat adjustable Gen 3 guide rod the user is able to tune their pistol recoil system to a specific cartridge load suppressor or compensator for added reliability and performance. Specifications for L2D Combat Guide Rod Reducing Ring Glock Gen 3-4: Manufacturer: L2D Combat Color: Titanium Nitride Fabric/Material: 17-4 Stainless Steel Gun Make: Glock Model Generation: 4 3 Features of L2D Combat Guide Rod Reducing Ring Glock Gen 3-4 Gun Model: Glock Gen 4 17-4 Stainless Steel Drop-In Installation Compatibility: All Glock Gen 4 pistols Finish Options Stainless TiN (Titanium Nitride) Black Nitride Chameleon pVD (physical Vapor Deposition) Package Contents: L2D Combat Guide Rod Reducing Ring Glock Gen 3-4 L2D Combat 3HD-PP1-GG4GRRR: Glock Gen4 to Gen3 Guide Rod Reducing Ring Titanium Nitride