The Yuasa SWL 3300FR Battery range from Critical Power Supplies is an enhanced NPL design resulting in an improved energy to density ratio, giving up to 40% extra discharge capacity. All other attributes and operational characteristics are the same, thereby maintaining the benefit of a common mechanical and electrical design for users of both products.h2. Features And Benefits- Yuasa VRLA batteries can be used in any orientation excluding continuous use inverted.- Standard case material is flame retardant to (UL94) HBØ.- FR option case material is flame retardant to UL94:VØ (oxygen index 30).- SWL batteries are manufactured in factories that comply with ISO9001:2000.- FR option SWL’s comply with BS6290 Part 4 (1997).- SWL batteries comply with IEC 60896-21+22.