This is a Bright Source Emergency 3 Cell Battery 3.6v 4.0ah, a D cell nickel-cadmium rechargeable battery with flying leads, ideal for use within emergency lighting applications. These batteries are often used with emergency bulkheads, polo fittings and with LED panels and downlights for emergency uses. Typically used in offices, corridors, exit areas, schools and public buildings. These batteries have been manufactured to be used in fittings with limited space. Tied together with cable ties which can be cut to manoeuvre into tight spaces or fittings. Please note that Ni-Cd batteries are supplied with a residual charge and should be charged at the continuous charge rate before use.