Oz-Hammer- Driver for Jackhammer: Oz-Hammers are REQUIRED for customers that want to drive the Oz-Posts in the ground with a jackhammer. Some Oz-Posts require Hammer-Spacers to be used in conjunction with this driver. Please see the list below or the Oz-Post product specifications. Our exclusive Oz-Post driver is a high grade steel attachment that fits most common jackhammers that are available today. If you are planning to rent a jackhammer most rental centers have Bosch® Brute or Wacker® 60# electric jackhammers that are perfect for any size job. There are also gas powered jackhammers (Wacker® model BH-23 is one popular brand) that are great for remote locations where power cords or generators would have difficulty reaching. Air operated jackhammers also work, but is not recommended because they are very heavy and much more difficult to handle. There are many other jackhammer brands and most of them will do the job. Ask the rental center to clarify that the jackhammer has a 1 1/8” hex chisel holder with a retaining collar. Be sure to check out our own line of Jackhammers like the EL-1000 and GP-1200. They are specifically designed for driving Oz-Posts. Specifications: 1 1/8” hex chisel holder with a retaining collar. For use with (no Hammer-Spacer™ required): ISW-850, IS-600, I2-850, I2-600, Hammer-Spacers required for Oz-Post Models: I25-850, I3-850, T4-850, T4-600, P4-850, P5-850, T46-850, S4-850, S4-600 and T6-850.