THG-xxxS series step up/down transformer is specially designed for such electronic equipment which rated AC voltage different from that of the local netvoltage.Full plastic cover .Prfect design. They are safety for use within the rated voltage range. ----Input voltage:AC110v or 220v 50Hz/60Hz ---With fuse protector ---Output voltage:AC 220V or 110V 60Hz/50Hz ---Built AC110v/220v woltage selector switch inside ---certification:CE,CQC ---Warranty: 1 year. ---Product list: THG-100S---USD3.33---40*1*9.5*37.5cm---25pcs/ctn---27/25kgs---100VA THG-150S---USD3.89---38.5*37.5*18.5cm---16pcs/ctn---23/21kgs---150VA THG-230S---USD5.00---38.5*37.5*18.5cm---16pcs/ctn---25/23kgs---230VA THG-300S---USD6.67---37.5*29.5*18.5cm---12pcs/ctn---22/20kgs---300VA THG-500S---USD8.89---38*18.5*24cm---6pcs/ctn---18/16kgs---500VA