Philips LED Daylight Deluxe Linear Fluorescent T12 Light Bulb: 4-Foot, 2325-Lumen, 6500-Kelvin, 40-Watt, Bright White, Bi-Pin Base, 10-Pack

The lights are working great so far.Time will tell.

Fit perfectly and lit up the office space

Dirt used to be the usual reason a fluorescent lamp wouldn't light when it was humid. In F40 needs about 200 volts end-to-end to strike the arc. Damp dirt could cause enough electrical leakage to draw the voltage below 200. I could usually fix a troublesome tube by washing it in the shower.My house uses nine F40T12 tubes. Most had been in use more than 20 years. A tube that's failing usually gives plenty of notice by blackening at one or both ends. It may continue to work for years, but it's fading away. Some of mine had blackening, and one day, one would no longer start. I ordered from Amazon because, not having replaced a tube in years, I forgot I had a spare. I'm glad I forgot!The manufacturer used a simple box with a separator at each end to keep the bulbs from hitting each other. Amazon wrapped the box in the kind of bubble wrap that's a little over 1mm thick. and put that box loose in a larger box. It looked disastrous, but the tubes seemed OK. I didn't know fluorescent tubes were so tough!The old CW (cool white) produced a lot of lumens. It was efficient for reading, but the Color Rendering Index was only 62. Mostly green and yellow, it was gloomy at low levels. Warm white colors were too orange for me. Daylight colors were too blue. I preferred CWX. It was less efficient than CW, but at 78, it had a better CRI than other colors. I found it more cheerful, and blues and reds showed better.When Amazon's description called these bulbs Daylight Deluxe, I remembered the old Daylight, which also had a color temperature of 6500K. The CRI was 58. I thought I wouldn't like the color of these new tubes, but at least they'd light when I flipped the switch. I was so pleasantly surprised that I found the Philips data sheet. The CRI is 90!I replaced the failed tube. Then I replaced a CWX with a darkened end. Being new, the Philips was brighter. I also saw a better color. It was such an improvement that I got a stepladder and replaced all tubes with blackening. I may end up replacing tubes without blackening because I prefer the color.I had occasional failures to start in the bathroom and the kitchen, two rooms where the humidity is sometimes high. The bulbs looked clean, and washing was not a lasting solution. That left one possibility.Glass is hydrophilic. In humid conditions, enough water molecules can stick to make the surface damp. Fluorescent tubes used to have a coating to repel moisture. It seems these tubes have not been treated. Rain-x is a water-repellent coating for windshields. I have some Rain-x somewhere, but the first thing I spotted was an old can of silicone spray intended to make clothing and leather water repellent.I wiped some onto the two bulbs exposed to high humidity. After a year, during a rainy spell when indoor humidity reached 78%, I had trouble again. Dust had stuck to the coating. By now I'd found my Rain-x. I washed off the old coating and applied it. I haven't had any trouble since.

Worked well when I changed the ballasts in my ceiling lights!

Perfect for my garage! A few lights in our condo's 5-car garage started to burn out, and the old lights were old (GE ecolux w/starcoat f40 cx 65). This was a perfect fit! Fair price, too

Great price for Fluorescent bulbs, and everything arrived in one piece. The four that I used worked with no problems, and was the brand that was advertised. They’re Philips bulbs so I expect them to last.

Over the years ive used 4-5 boxes of these from Amazon ! firstly their always packed to the max have never had any of the bulbs broken, maybe overpacked would be a better statement, great value as always !

I think these are old bulbs. I say that because it took about 10 minutes to light up after installing and turning on. I installed six in three different fixtures. One set still takes a few minutes after turning on to light up.