I replaced nine 300W 120VAC incandescent light bulbs with these 50W 3000K warm white 6000 lumen LED bulbs. A large E26 based E39 mogul base was required so I'm glad it came with the bulbs. The brightness is much better than the old 300w incandescent bulbs and the energy saving is amazing. The only downside is that these bulbs are not dimmable, but they will work with dimmers if the dimmer is fully on.