Check the listing for details. Solar Panel Strut Mount Block. Color: Black, Condition: New. Listed at 5.00 USD. After years of searching for an easy solar panel mounting system that you can quickly put together without freight shipping from some distant solar store... This mounting system uses standard electrical struts you can find in any electrical supply store. One problem to solve is aluminum and steel does not mix well. Our mounts keep the solar panel frame from coming into direct contact with the steel strut frame. Made from a nylon composite material the plastic resists UV light and high temperatures. Using a square steel washer over the top of the mount helps protect from plastic failure over time. This uses 2 T blocks that clamp the panel secured by a 3/8" bolt. A square washer is used to support the plastic. This system does not provide a grounding point for the panel. You must provide proper grounding for the frame.Use at your own risk. Secondary protection must be supplied to prevent panels from falling out on tall buildings. Order the proper thickness for your panels. Large new panels are often 40mm thick while the low cost 100 watt panels popular on ebay are 30mm thick. This sale is just the plastic blocks. You need a square washer, bolt and cone nut that locks into the strut. Buy the correct 3/8" bolt length. 3" will work for the larger panels, 2.5" is better for the thin panels. Do not over tighten. Contact the seller if you need a different size panel thickness.