Fits Ariens machines with 3″ bolt spacing (you may need spacers). This extreme duty replacement set of 2 snow blower shoes is designed to lift snow blowers up over sidewalk cracks up to almost 2 in. Bottom runners are 12 in. long, and are CNC cut from 1/4 in. thick steel plate more than twice as thick as many stock skids. The leading edge of our skid is moved forward to protect and gently lift snow blowers up over bumps. The angle of the leading edge is less than half that of most stock skids. For every bump the skid encounters, it has more than twice the distance to lift the snow blower up, compared to a stock skid shoe. Made with American Steel. Gravel is brutal on snow blowers. Stock skids dig into gravel, leave ruts, and bend when they encounter frozen rocks. Mount skids with wide-tip forward to provide a ski-like glide over uneven terrain such as gravel.