Pneumatic energy lockout device, 3.50" (88.9mm) diameter x 0.10" (2.5mm) thick.FEATURES:• Pneumatic energy devices can be locked out quickly and easily without costly tool modifications or inconvenient in-line valves• When installed on the male pneumatic fitting, prevents the ability to engage into the female fitting• Universal compact design makes the pneumatic lockout device easy to transport and install on almost any fitting, even in tight spaces• Rugged stainless steel construction offers superior strength, durability, added security and corrosion resistance