MasterVolt Solar ChargeMaster - SCM20 PWM One Size. Suitable for both 36 cells panels (in 12V systems) and 72 cells panels (in 24V systems). Its protection against water spray suitability for high ambient temperature and compatibility with negative grounding make it the perfect solar regulator for marine and mobile environments. Optionally a temperature sensor is available. Safe User Friendly & FlexibleThe SCM20 PWM is suitable for all types of lead-acid batteries in both 12V and 24V. The device features a large display and switchable output with evening / night lighting function. Specifications for MasterVolt Solar ChargeMaster - SCM20 PWM: Manufacturer: MasterVolt Color: Blue Package Contents: MasterVolt Solar ChargeMaster - SCM20 PWM MasterVolt 131822000: Solar ChargeMaster - SCM20 PWM One Size