Shout-out to #HLG for the excellent customer service and product support. I recently ordered 4 quantum boards for a project and upon receipt, every one had at least 1 broken/cracked Diode Crystal. After 4 emails and 4 days I have 4 brand new boards in hand at no cost. Best customer service I have experienced. Will definitely recommend HLG. and as an electrical technician I would love a chance to be part of any product testing in the future.

I built 2 separate light bars . Each having two qb-96 leds hooked up to a HLG-320H-C2800B driver, I put a dimmer on it . It’s versatile enough to put into a 2x4 as a single or teamed up together for up to a 5x5 . I had both in a 6x6 room and they crushed it , the buds were super solid . The penetration down to the lowers was excellent. It might even be too much for a 4x4 with out a dimmer .The lights did need a fan on them to keep them cool . While these are not as efficient as most out there now I like that I can just replace the led for 50.00 each when they burn out . I find it more environmentally friendly than growing out a huge fixture in 5 years. These lights are great and can be pushed hard. They are super versatile, and the end product is excellent.
I had a technical question and I left a message w hlg support and never received any support . I figured it out myself, I was super let down by them...

I'm updating my review June 30th I recieved 2 of these light engines and 1 of the boards was damaged, exactly 1 week later a replacement board came in the mail, excellent customer service, I'll definitely do more business with them!

I have several diffrent high and mid power lights I grow with and my very best grow was was with one of these, I ordered 2 more because I was so happy with the results, one of the boards came in damaged, 3 of the red diodes had messed up, or popped off domes on the diodes, I contacted them on the phone and by email for a replacement, I would give 5 stars otherwise this is an awesome light, I will give an update when they replace the damaged board

These things are amazing. I was using 4, 2 each on an HLG-320-54-A, and putting them at full power evenly spaced will burn buds in the corners of a 4x4 if you're not careful. I ordered 2 more so I can have more even light distribution and still be powerful enough to flower a 5x5 with great numbers in the corners. Great little lights.