Euclid Gladhand Seal, Universal with Excluder Flap.
Gladhands are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer. The couplers have a rubber seal which prevents air from escaping. To connect the gladhands, the driver presses the two seals together with the couplers at a 90° angle to each other. A turn of the glad hand attached to the hose will join and lock the couplers.