They are a Gel Cell, and they are worth it. You do not have to worry about loosing any fluid out of the battery, no matter which way you mount or tip it, or the battery venting out any hydrogen gasses. They are truly a maintenance free battery. Because they are sealed too, you never have to deal with any of that nasty corrosion on the connectors that is typical of a lead acid battery. I run a Red Top (~$80.00) in my 79 F150 and a Blue Top (~$140.00) (deep cycle marine) in my XJ so I have the extra posts to hook additional things up to. I have been running them for about 5 years now and never had one problem.

Sean