Three O-rings are visible at the base of each test tube-style lamp cover. Two of these O-rings are recessed below the glass and provide the watertight seal. The purpose of the third O-ring is often overlooked. In the event that the lamp cover was struck by an object, the third “bumper” O-ring comes into play. The bumper O-ring absorbs the shock of the impact and acts as a means to protect the lamp cover. When combined with the extended cowling of the Halcyon Goodman handle reflector, the bumper O-ring offers unprecedented protection of the light head. The combination of the cowling and the bumper O-ring provides significant protection so that Halcyon 18-and 21-watt HID lamps do not need a flat plate lens cover of any kind.