Sunblaster Full Spectrum High Output T5 Lamps 36" long Utilizing Cold Chamber Technology Providing 10,000 Peak Lumen Operating Hours Rated at 39 Watts, 3627 Lumens, CRI: 81 I have 8 of those ( selling lamps only, no fixture) that have been used for few years, so I expect that the 10,000 peak lumen operating hours has been reached or exceeded. I used them in rows of 2 for 18" wide trays and this year the seedlings were growing long and thin, so I replaced the lamps. These lamps are still in working condition, but not for growing plants anymore, so I am selling them as regular lighting lamps. 8 lamps for $20