I was very skeptical of them.But, they do work and they work very well. I have an older Champ that I have modified the livewells. Added 2 recirc pumps, oxygenator, overfill the wells by approx. 10 gallons, etc. This summer during our 3.5 hour jackpots water temps were in the low 90s. Our fish seemed to be healthy, but nothing spectacular. You could really feel the heat off of the water when the lids were opened for whatever reason. Fished a tourney with my buddy who has an older R boat. IMO, the older R livewells are the worst ever made, as far as keeping fish alive. All he has one recirc pump, no fancy gadgets other than VT-2 vents. Water temp was the same 91-92 area. We put in a bottle of frozen water around 530. At 10 when we pumped the water out, the water was still cool. Our fish were in great shape and hard to catch in the box. No doubt in my mind the vents help. Just my .02, but they are worth the 40 dollar investment.