T8 LED 4 X Tube Ballast Bypass 4ft Day Light Color 4500K 3,000 Lumens | 22W Frosted Cover | Plug & Play Commercial Grade Lights, Dual Ended Power | Fluorescent Replacement (4 Pack)

These are double-ended tubes, meaning you need to attach line power to one keystone and neutral to the other (there is a small graphic on the package to show this). Converting an existing fluorescent light fixture to use this bulb was relatively painless, i.e. remove existing tubes, remove ballast, wire neutral and line to either set of keystone(s), and re-assemble the case. All in all, about 10 minutes per light fixture, assuming the light fixture gives you easy access to the ballast and wiring inside. Have a collection of wire nuts, electricians pliers, and a screw driver handy.These LED tubes cast a very bright, white light. Compared to the 34W T8's they replace, they are more directional but also brighter in the direction that they principally shine in (but the diffuser lens helps). The light is very uniform across the tube, as is the color temperature. One of our bars had a "dead" sector (maybe 4" long), that then decided to restart and light consistently ever since. The tubes are relatively light and I'm not convinced that the LED strip is very well bonded to the aluminum extrusion that makes up the "upper" part of the tube (some rattling inside). But it works and it doesn't get very hot.If there is one thing I'm not a fan of, it's that the time from application of power until the light bar lights is noticeable. Whereas the old magnetic-ballast fluorescent tube would flicker and hum on startup, these light bars stay dark until they finally pop. But, unlike fluorescent tubes, the LED starts full-on, i.e. does not take time to come up to full brightness. So you just have to get used to the delay.The tubes came quickly and very well packaged. While individual tube packages were very skinny, the outer cardboard box was sturdy and featured corner reinforcements. Tube boxes were taped to each other to prevent rattling.