99% sure it's a WFCO unit. It's supposed to be a 3 stage unit, Bulk 14.4v, absorption 13.6v & float 13.2v. Just replaced my WFCO 8955 with a Progressive Dynamics 4655 direct replacement due to OEM unit being stuck in float mode. Battery voltage can be 11.8v, turn every light, fan & tv/dvd on and charger still wouldn't go into bulk or absorption mode. I've noticed my two group 27's aren't performing well, I'm sure they sulfated up due to lack of charge. Will replace with two Interstate Pro ECM group 29's this spring.....