A good choice of carabiner shape can increase ergonomics and safety for certain uses.
The shape of the carabiner frame has an influence on:
• major axis strength
• load distribution
• gate opening size, and capacity
• strength in certain positions
• ease of handling
Another less obvious effect is the balance of the carabiner itself: for example, pear-shaped carabiners rotate more readily, which can result in poor positioning. D-shaped carabiners tend to stay in place better.
Talk to your local Petzl retailer for more advice on which is the right shape carabiner for your application.
Here are the basics on carabiner shape.