When to choose (3000K) 1) You know you like it, you know you want it
2) Desirable for spaces you might occupy before bedtime; promotes sleep
3) Slightly lower brightness than the 5000K bulb.
When to choose (5000K)
1) You know you like it, you know you want it
2) Desirable for daytime work spaces; promotes alertness
3) Slightly higher brightness than the 3000K bulb.

Peak wavelength: the “last mile” in lighting design (high R9 again) No one (and I mean no one) talks about this (except Jon), but it’s the difference between good and bad. In other words, manufacturers aren't telling you the whole story if they don't show their R9 ratings. Our bulbs have a “true red” 635nm peak wavelength. I tested it myself and you can see it in the images below. This peak wavelength is critical in achieving high R9 and saturated reds. Many bulbs that are 90+ CRI still look bad because their peak wavelength shifts green or yellow...Remember your superpower? Combine this with a low R9 and your regular "High CRI" bulb isn't cutting it. I guarantee if you compare them you can tell the difference, and you are going to choose the "better" bulb. Remember those trade show tests? 97% !!!

CRI is a measure of color reproduction accuracy. Sunlight is a perfect 100. These bulbs are rated at 95+ and the ones I tested were all 96 or 97. Don't trust any manufacturer that omits R9 values (this bulb has a 92 R9). ANSI minimum indoor lighting standard is 80 CRI...which is fine, but it's not great. This standard only requires the basic 8 step measurement, not the complete 15 step measurement. You spend a lot of time in your home and "fine" is not an admirable standard for something you spend so much time living with. You deserve great and this is it. High R9 (true red) values: Many "High CRI" sources score a 50 or lower on R9 (true red). Ultra High CRI is only achieved with high R9. Not using the extended CRI measurement is how companies get a high rating but still perform poorly in the real world. R9 is especially important for skin tones and many natural things like food, wood, etc. The human “super power” is distinguishing color...why use lights that limit that? We tested High CRI against low CRI at a couple of trade shows. We showed people two lights that were identical, except for CRI...and 97% of people picked High CRI based on the simple question, "which one would you choose." People NEVER agree on anything at 97%.

These bulbs measure 95+ CRI using the more stringent "15 step index." They also achieve an 92+ at rendering saturated reds (R9)...which is unprecedented. Many companies use the antiquated "8 step index" in order to make their CRI number higher, and the 8 step index ignores R9.

These bulbs are dimmable between 10%-100% output when using an Triac dimmer switch, a traditional dimmer circuit.

This is basically a different form of brightness control from dimming. It also allows you more targeted illumination if you need it. Brightness is also related to the distance from the lamp to the target surface, so you can adjust "apparent" brightness by either focusing the bulb or changing the distance.

These bulbs feature a huge heatsink to increase the lifetime of the LED. The blub is quite heavy because of this, but that doesn't matter in most situations...just FYI.