Drive a wide variety of post sizes with just one driver! The REDIboss78 is a gas-powered post driver with a 3 1/8" guide tube powered by a HONDA gx35 engine. Purchase of this driver includes the REDIslvboss78 reducer for driving smaller posts up to 2". This is the largest & strongest gas-powered post driver on the market and comes with a 3-year warranty. Reducer sleeves in a variety of sizes are available for purchase separately.