Oil Saver 2 : A packing arrangement that seals around a wire line to prevent leakage and waste of gas, oil, or water (as when swabbing or reworking a well). It may be operated mechanically or hydraulically. (WLOP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}