PR18 Standard Flashlight PR Replacement Light Bulb: Description - Standard replacement flashlight bulb - 7.20 Volt - 0.55 Amp - B-3-1/2 Single Contact Miniature Flanged Base (P13.5S) - C-2R Filament Design - 5.0 MSCP. - 3 Average Rated Hours - 1.25" Maximum Overall Length - 0.45" Maximum Overall Diameter - Typically found in flashlights using six "D" cell batteries.PR18 Standard Flashlight PR Replacement Light Bulb