The BR40 LED reflector 4-pack is ideal for extensive contractor projects. home renovations. or upgrading an existing fixture. The size and shape emulate halogen lamps, and these bulbs are dimmable with a variety of dimmer types. The BR40 4-pack's smooth heat sink and bulbous shape closely resemble halogen lamps. Each bulb is long lasting, fully dimmable and screws into any E26 standard screw base.