2.Tianjin Grewin Technology Co., Ltd. is a manufacturer of toroidal transformer, EI power transformer, current transformer, PCB, etc. We have obtained ISO, CE, VDE and RoHS approvals. Our company has many advantages, so we can be your honesty and reliable supplier: 1) We can supply goods in required shipment date. 2) We'll seriously take each enquiry from our customers. Quick reply and quote in time! 3) We can design products according to your special needs. 4) We cooperate with customers in Italy, Spain, America, with OEM or ODM service and we have many years' rich export service experience.