Circline LED light bulbs are energy saving replacement for traditional circular T9 fluorescent lamps. Circline LED Lights feature a polycarbonate cover, die cast aluminum heat sink, and high lumen output LED for the highest level of brightness and color rendering, and external power drivers to remove heat build-up inside the tube. Instant full brightness, extremely long operating life, no flickering, shatterproof, these lights combine cutting edge optical and mechanical design to realize a light distribution that outperforms fluorescents circlines, which makes them the perfect choice for ceiling fixtures, commercial and industrial applications. Circular LED lamps provide a direct retrofit to circular T9 fluorescent lamp and ballast with virtually no modification necessary to a new or existing fixture. Circline LED lights are also occupancy sensor compatible. Fluorescents are not suited to occupancy sensors because their filaments burn out extremely fast with repeated on off cycles. Now with LED lights, you don't need to concern yourself with early bulb death. Go ahead and add an occupancy sensor and multiply the energy savings.