LSG PAR38-style grow light sale
I noticed this Black Friday deal until Mon.
$99 for 4x 13W bulbs (normally around $160).
Here is the spec:
PPF of 21.70 micomol/s from 13 W, which is 1.67micomol/J efficiency. Some of you may not know how to interpret the specification, but this is pretty much at the top efficiency of the LED and HPS grow light according to this independent test. Light Science Group (LSG) and the BML delivered the top level efficiency in this test. The test was with a bigger model.
The beam angle is 40 degree, so you can place it far away from the plants. At 24", it delivers 150 micromol/m^2/s, which is at the Cattleya level light (or slightly lower than that), and covers about 16" diameter.
Even with the sale price, it is fairly expensive, but it is a very efficient one (so you can save money in a long time (a couple years)). With DIY COB, we can get a higher efficiency for less money. So I personally wouldn't buy it, but some people may be interested in this kind of screw-in bulbs. There are lots of crappy PAR38 style LED lights, which are not worth getting, but you shouldn't confuse this LSG bulb with the cheap ones.