Helmet or head gear when not in use. The clamp is made from aerospace grade 6061 T6 billet aluminum and hard anodized with a durable black e-coat which is fade resistant! 
 
The clamps come in 4 sizes - 1.5, 1.75, 1.875 & 2 inches. The clamp is flat on one side so it can be mounted to the cage under the roof skin. Don't just leave your valuable gear laying around! Hang it up!