Diode Dynamics Warm White 39mm SMF2 LED Interior Bulbs - Pair New Interior LED Bulbs - 3000K Warm White 39mm SMF2 LED Bulbs - Pair For Door / Dome / Trunk Lights Plug Play Installation Stage 2 Brightness - 24 Lumens per Bulb Warm White Color Qty: 2 (Two) LED Bulbs Design. The 39mm SMF2 LED bulb is a direct replacement for any 39mm-size bulb, commonly found in door lights, dome lights, and trunk lights in many vehicles. Populated with two 5050-size SMDs, the SMF2 upgrades the factory yellowish incandescent bulb to a more modern LED appearance. The SMF2 was designed with an embedded load resistor and implanted diode for superior reliability. With its durable metal terminals, it will fit snugly in the socket, and its light weight means it won't vibrate loose over time. Reliability. Unlike other bulbs on the market, this bulb is built with constant-current circuitry, along with transient suppression. That means this bulb will last for years, not months, with no flickering or failure. And like every Diode Dynamics product, it's backed by an industry-leading three-year replacement warranty. Brightness. With 24 lumens of true, measured output, the SMF2 LED will provide slightly more light output than your original 39mm-sized bulb. If you are looking to increase output, we'd recommend checking out our HP6 option! All Diode Dynamics LED lighting is rated with accurate, measured lumen figures, not calculations or guesses. We test the true output in-house, and provide you the real numbers to compare.