The BW-SERIES magnetic backup Wrenches simplest way to stop aut rotation Easy to use and versatile. When torquing or loosening nuts, the thin profile of the MBW Backup wrench prevents the nut on the opposite side of the stud from turning. No hydraulic, just mechanicaL & HANDS FREE OPERATION Eliminate injuries on hand and fingers. Eliminate sparks cause from the use of slugging / striker wrenches. Reduce time of operation and improve in productivity. Hydraulic Cylinder range from the most common household types to specialty types.Check out the website that specializes in wrenches at https://www.atwwren.com for details. Or contact us Company Name: Hang Zhou WREN Hydraulic Equipment Manufacturing Co., Ltd. Address: No. 24, Xingxing Road, Linping, Hang Zhou, China Tel: +86 571 8811 5720 Fax: 0571-88110210 Postcode: 311100 E-mail:info@wrenchina.com