Yantai Yunhsheng Petroleum Machine Accessories Co., Ltd., founded in 1997, is a professional manufacturer of API 11B Sucker Rod Couplings, which covers Spray Metal Coupling[SM], Class T coupling[T], Change over Coupling[SUB OD], Full Size and Slim Hole, with the size of 5/8", 3/4", 7/8", 1", 1-1/8". All of them are excellent in Quality and reasonable in Price, and the production and inspection are being done fully in accordance with API 11B standard. We got our API 11B Certificate for couplings since last June, the Certificate No. is 11B-0088, and we began our International sales since then. Only one year and a half, we have exported our couplings to America, Peru, Argentina, Kuwait, India, Indonesia, etc., and established longterm cooperation with many of our customers home and abroad, based on our good quality and Service.