Maglite LED Conversion and Upgrade kits: The best and cheapest dropins and replacements..
HQRP High Power 3w LED Bulb for Maglite 2D 3D / 2C 3C Cell Torch Flashlights Conversion Bulb Upgrade plus HQRP UV Meter
HQRP Ultra Bright 300Lm High Power 3W LED Conversion Upgrade Bulb for Maglite Magnum Star II 2 Replacement fits Mag-Lite 3-4-5-6 D/C, 3-6 D C Cell Lanterns Flashlights Torchs 3.2v - 9V + Coaster
Litt Industries 350 Lumen Maglite LED Bulb & Lens KIT for 2-6 Cell