Steel carabiner made of 10mm wire with screwgate. Carabiners come in four characteristic shapes: Oval: Symmetric. Most basic and utilitarian. Smooth regular curves are gentle on equipment and allow easy repositioning of loads. Their greatest disadvantage is that a load is shared equally on both the strong solid spine and the weaker gated axis. D: Asymmetric shape transfers the majority of their load onto the spine, the carabiner's strongest axis. Offset-D: Variant of a D with a greater asymmetry, allowing for a wider gate opening. Pear/HMS: Specialized oversized offset-D's used in belaying. These are usually the heaviest carabiners.