ST series step-up & down transformer is specially designed for such electronic equipment whose rated AC voltage different from that of the local net-voltage. They are safe for use within the rated voltage range. ----Input voltage: AC 110v or 220V. ----Output voltage: AC220V or 110V. ----With several plugs to choice: U.S./Britain/European/Italy/Australia/South Africa Std. In addition ---With fuse protector. ---With International usually socket and fuse protector as accessory ---Certification:CE ---Patent No:ZL 00 3 06379.8 ---Warranty: 1 year. ---Rated power: 50watt~20000watts ST-100W---39.5*31.5*24.5cm---12pcs/ctn---20.5/18.55kgs ST-200W---39.5*31.5*24.5cm---12pcs/ctn---26/245kgs ST-300W---35.5*31.5*24.5cm---8pcs/ctn---29.5/27.55kgs ST-500W---46.5*19.5*24.5cm---6pcs/ctn---26.5/24.55kgs ST-750W---31.5*22.5*34.5cm---4pcs/ctn---22/205kgs ST-1000W---30*25.5*34.5cm---1pcs/ctn---9/85kgs ST-1500W---30*25*21.5cm---1pcs/ctn---13/115kgs ST-2000W---30*25.5*21.5cm---1pcs/ctn---15/135kgs ST-3000W---34*25.5*21.5cm---1pcs/ctn---15/135kgs ST-4000W---34*25.5*21.5cm---1pcs/ctn---24/225kgs ST-5000W---39*28.5*21.5cm---1pcs/ctn---26/265kgs ST-10000W---39*28.5*21.5cm---1pcs/ctn---30/285kgs