The L Series plugs have a tapered design with a lift-tab feature to facilitate removal. Great for small size openings and in tight areas where a side tab would not be preferred. Pulling the tab exerts an off-center force which breaks the seal between the plug and wall of the opening.:: a: 1.844, b: 2.000, C: 2.12, D: 1.00, F: 2.12.