Crab minimum size tool (Ireland)

This is a tool used for measuring either Brown (Edible) crabs or Spider crabs caught in Ireland to ensure they are above the minimum size to keep.

Brown crabs must be a minimum of 140mm, male spider crabs 130mm and females 125mm.

The gaps on the 2 sides of this tool measure 140 and 130 respectively to quickly measure Brown and Spider crabs for those who are unsure how to distinguish male and female spider crabs.
 

https://www.sfpa.ie/What-We-Do/Sea-Fisheries-Information/Useful-Codes-Conversion-Factors-MCRSs/Minimum-Conservation-Reference-Sizes-MCRSs-