Doryman Shellfish Calipers can be set from 3 to 6 1/2 inches to measure lobsters and crabs to specific legal sizes. While they float, these calipers also employ an attached lanyard to avoid any dropping mistakes. When the caliper is fully extended it becomes a 9 inch straight edge rule. When collapsed it can easily fit into a pocket. An easy twist knob regulates the calipers size and can be used to lock in measurements.
