Power pack is 15" in length. The Magrath Stock Prod Power Pack is designed to help handle and move livestock effectively and efficiently. As a market leader, it has proven itself on the road and in the stockyards for over 40 years both in the US and throughout the world. Time tested and proven effective. 4 high amp alkaline size C batteries included. Power Pack only, shafts sold separate. High energy, longer lasting alkaline batteriesDurable, reliable solid state electronics systemTransmits very low current to animal with strong, instantaneous joltFinger guide to find switch by feelRubber switch insulator for prevention of feedbackPrecious metal battery contacts won't corrodeHeavy coil spring assures firm battery contactTough, structural grade plastic case | Springer Magrath Stock Prod Power Pack