DYN1930 Metered Glow Driver w/Ni-Cd, Each Dyna-Glow glow driver features a durable red-anodized aluminum case. The Sure-Lock? glow plug attachment secures the Dyna-Glow around the body of the glow plug for hands-free starting. The contoured Comfort-Grip? finger clip makes installing and removing the Dyna-Glow easy and virtually slipproof. The Metered Locking glow drivers let you easily see if the Dyna-Glow is drawing a current when attached to the glow plug.