2139 Bandito Aluminum Lobster Gauge. Used to make sure your lobsters are of legal size to keep by measuring the Carapace part of the lobster. The gauge must NOT slip over the carapace for the lobster to be legal in Florida. Includes a hole for an easy attachment point. Check your local regulations for the proper use of lobster gauges. A very sturdy 1/8” thick x 5 ½” long. 3” gauge opening. Required by law when lobstering.