A top bracket / plate designed to hold accessories like the asiair on my skywatcher evostar ED72 telescope tube rings. The ring spacing is 120mm and designed for the ¼ // M6 through bolts, the nut insert is m6 standard size. The risers are 30mm tall to allow a dew heater strap to sit on the lens hood. it also includes standard m4 accessory bracket to allow a dovetail mount or other accessories (the asisir plus) to be connected to it. It also helps with balance / weight distribution to allow better balancing. this gives you Lots of options.