EMI has recognized the need for a versatile yet convenient multi fire/rescue tool. The results... The 511 Tool. Capable of five different functions; adjustable hydrant wrench; spanner wrench; gas shut-off tool; pry axe head; striking hammer head, this tool is essential gear for all firefighters and emergency first responders. The 511 Tool is manufactured of high strength treated alloy. It is also non-sparking, corrosion resistant, light weight and can be worn easily on a truckman's belt.