They are bright, a perfect color, and look great in the light fixture. As you dim a fixture, the light usually changes to a warmer (more yellow) shade. They were encased in foam to eliminate touching another bulb or moving during shipment.

The product description for the 60w 4000k bulb is misleading. It says the bulbs are both 4 watt and 6 watt. A 6-watt led bulb is about the equivalent to a 60-watt incandescent bulb.

Cotanic's claim of a three-year warranty is empty. No response from manufacturer. Was contacted by provider and issued a refund.

Installation is exactly like replacing your existing florescent bulbs. Removing the ballasts is a pain, but rigging up the wiring is simple enough. Work with or without ballast, single end or double end power.

Love the duel end connections. Came package so well they couldn't get damaged in shipping.

No issues at all, and no dead bulbs in the 20-pack. No more dimming fluorescents or ballast changes. Can't speak on longevity as bought and installed first batch of 20 (redo 5 light fixtures) in january and just purchased another box and did 3 more li...  Read More

Excellent brightness. Good color, no flicker, no hum. Bright, instant on and relatively easy to install.

The parmida led is about 10% brighter than the new fluorescent bulb. Brightness is a little better than the classic fluorescent tubes.

Each time i flip the switch off/on different one's come on and different ones don't come on. Finished the install, turned power back on and flipped the switch and nothing. Removing one of the bulbs (only one bulb connected) allows the bulb to turn on,...  Read More