This hand held post pounder that drives post up to a 3 1/4" diameter (83mm). Details and Features: PP83 Post Pounder Safety Glasses Ear Defenders 3 inch to 2 inch reducer User Manual The 83mm Post Pounder uses a 4 stroke Honda Engine yielding a powerful 1720 bpm. Free Shipping to the 48 continuous States. Designed with the professional fence installer in mind, Post Pounder 83 will drive any shape post up to 3 ¼” in diameter, quickly and easily. Drives T-posts, round posts, angle post and U posts with ease. Makes quick work of sign post installations. The quickest and safest way possible to install erosion fence wood stakes. Saves you time and money. Hey look, no hoses, no compressor… this design enables the operator to move along a fence line with ease much faster than traditional air and hydraulic driven units. The Post Pounder 83 has zero set up and pack up time.