I bought the 8 pack of these to use as grow lights. The set of eight was the cheapest per lumen I could find from a product with good reviews (17600 lumen for $50).ConstructionEach tube has a translucent cover with a square profile, most likely made of styrene. For my purposes I need max light output, so I removed them. They remove and snap back in easily so it won't be a issue to experiment with what option you like best. The "thick alu" is roughly 0.3mm standard aluminum extrusion. They are extremely lightweight and do flex quite a bit, but this should not be a problem as these are not designed to be portable fixtures.The kit included a lot of accessories (see picture). There are 19 brackets, 18 screws, 8 socket covers, and 8 extenders. These extenders function the same as the "connecting cords" except they allow bars to be connected end-to-end without any visible wires. As stated in product description, there are also 6 connecting cords (20") and 4 switched wall plugs (5'), both about 20AWG. This is on the thin side, but is fine for the small amount of current these draw. A note was included with the lights that cautions not to daisy-chain more than 6 lights--this keeps current within recommended ratings for 20AWG wire (<1.5A). The same gauge wire is used internally to bridge the power connectors. Note that the plugs are non-polarized and do not have a ground wire (despite the ground pin on the bars themselves). If these get submerged in water there is the potential for issue, but it is unlikely due to the relatively well-sealed tube.People have been complaining that the brackets are not strong enough, but I don't see the issue. Yes, they are thin and bendy, but the light bars are so light that the strength is sufficient. Once these are installed, they should hold the bars perfectly well with no fuss. If they do end up falling out, the brackets can be bent in slightly to better grip the bar.ElectronicsEach bar has a slightly flexible PCB that houses the LEDs and is held securely in a slot in the extrusion. This is NOT coated, so with plastic cover removed, the lights are no longer water-resistant. There are 96 LEDs per bar, and they are 2835 SMD type. These run at approximately 3.1V, and draw about 0.2A each. I don't have a light-meter to test the actual output, but the 2200 lumens stated in the product description are consistent with the specs for this type of LED. I would guess this is close to the actual output of the product. It is important to note that the "T5" moniker is more for size than flux. It is on par with a standard T5 tube, but it is less than half that of a T5HO. T5HO is commonly used in high-bay and grow light fixtures so be careful when doing comparisons with dedicated products.There is no noticeable flicker, and the light output is a nice cool white. 6500K is noticeably bluer than daylight (~5000K), so keep this in mind when picking the color temperature. For plants in the veg cycle, this is perfect.Each light bar contains its own DC power supply. This is wrapped in plastic and insulated from the aluminum tube, so there is not much to worry about. It gets warm, but not hot. The PSU is high-frequency enough to eliminate visible flicker, but this does cause problems with interference. There is a good amount of RF noise emitted by the power supply, detectable on an AM radio and with oscilloscope. I didn't notice any issues with other electronics plugged in nearby, so any interference could likely be mitigated by moving othre RF appliances a few feet away.Wrap UpThese lights fantastic to grow some plants or brighten a workspace. They're quick to set up and very cheap. For the price, the build quality is perfectly adequate. I would absolutely buy again.