The Omega Modified "D" Aluminum Carabiners are all individually tested and feature an asymmetrical D shape for easy handling! Exceeds NFPA/ANSI/OSHA strength requirements. True radii rope bearing surfaces.These aircraft-quality 7000-series aluminum carabiners are available in three different gate configurations: SG-screw gate. TL-twist lock. 3AL-three-stage auto-lock.