Stop struggling to move your heavy equipment around, and use these heavy duty, low profile machine moving dollies instead to move your Bridgeport, lathe or milling machine around your shop with ease. These are designed to be as low profile as possible, standing only 1.75" inches tall, to make them easy to fit under most machines, without having to jack your top heavy equipment way up off the ground. They also have an integrated mounting bolt to secure them in place, to make sure that they won't slip out when moving with a load on them. You can also permanently mount these if you choose, to make it easy to roll your machines in and out for cleaning and maintenance etc. All steel used is American made, and locally sourced from other small businesses in my area, and I personally hand make every one of these skates myself, in my small family owned machine shop in Rittman Ohio. This listing is for a set of 4 heavy duty machine skates, with a maximum working load of 15 tons. Thanks for looking!