PR20 Standard Flashlight PR Replacement Light Bulb: Description - Standard replacement flashlight bulb - 8.63 Volt - 0.50 Amp - B-3-1/2 Single Contact Miniature Flanged Base (P13.5S) - C-2R Filament Design - 5.0 MSCP. - 15 Average Rated Hours - 1.25" Maximum Overall Length - 0.45" Maximum Overall Diameter - Typically found in flashlights using seven "D" cell batteries. PR20 Standard Flashlight PR Replacement Light Bulb