Rabbit 4 : A device that is put through casing or tubing before it is run to make certain it is the proper size inside and outside. A drift mandrel. (ITOGP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}