Designs Our released designs are listed here. Click on any of them for a detailed page with links to the download. SL-15 3D Printed AR-15 Lower SL-9 3D Printed AR-9 Lower SL-308 3D Printed LR-308 Lower ORCA-15 Mostly 3D Printed AR-15 Stock System Grip System Hose Clamp Cover SL15-DR Double Rib AR-15 Lower Super Safety 3D Printed Active Reset Safety