"LED protection devices" on each LED in an array -- what's this? (Reef aquarium people use ...)

I stumbled across this aquarium/reef site while looking up spectra of various emitters.
This below is a quote from a long page

where they describe multiple iterations with a large group of people working on improving lights for their use.
Sound familiar?

But one thing I’ve never come across is mentioned here:

The people who wrote that are selling kits to aquarium hobbyists, and give an amazingly thorough description of binning, color mixing, and etc.
Far beyond what flashlight folks need, but I thought it would be an interesting reference: http://reefll.com/index.php?route=product/list&path=64

Looks like these devices LED Protectors | ESD Protection - Littelfuse

Thank you! quoting from that: