LanTac USA LLC Guide Rod Adapter Bushing, For 4th Generation Glocks to Utilize 1-3rd Generation Guide Rod and Spring, Stainless Steel Finish, Silver 01-GP-GRA-SS Precision 17-4PH Stainless Steel Adapter Bushings with ultra smooth bore and crenulated crown" for reduced friction performance and aggressive styling. Designed to work with 1-3 Gen Non Captured Guide Rod.