The Y50-N18L-A3 GEL is a 12 Volt 21AH GEL (Maintenance Free) battery. Requires no addition of water during the life of the battery. The Mighty Max Y50-N18L-A3GEL is a TRUE DEEP CYCLE battery that can be mounted in any position, requires no maintenance. When a Gel Cell battery is charged, no hazardous fumes escape the battery case, gases are processed within the battery itself. Common uses for the Y50-N18L-A3GEL: ATVs, Motorcycles, Personal Watercraft, Jet Ski's, Snowmobiles and more. The Performance and Characteristics of the YT12B-4 GEL Battery includes maintenance Free / GEL configuration, No leaks, spills or contact with acid, no acid mist and pollution to the environment when charging and discharging, High capacity: 10-20% higher comparing to that of VRLA, low self-discharging and durable for storage, nice ability for resilience after over-discharge and the capacity of high discharge current increases by 30% over VRLA, amazing performances in all temperature conditions. Polarity: Negative on left, Positive on right. Listing is for the Battery and Screws only. No wire harness or mounting accessories included.