The most common types of snap hooks are the pear-shaped, D-shaped, and the keylock. Pear-shaped snap hooks are designed with a rounded shape, which allows for easy connection to a wide range of objects. D-shaped snap hooks, as the name suggests, are shaped like a D and are used in applications where a strong, stable connection is required. Keylock snap hooks have a key-shaped nose that prevents the hook from snagging on ropes, slings, and other gear.
Snap hooks can also come in different sizes and breaking strengths, depending on their intended use. For example, smaller snap hooks with lower breaking strengths are commonly used in fishing and sailing applications, while larger, stronger snap hooks are used in industrial rigging and safety harnesses.