Our 4-Star Mega Hub Dome Connector is used as a base connector for all Sonostar Mega Domes, where the base is at ground level. 'Mega' refers to the size of the hubs and differentiates them from 'standard' hubs, which fit 1/2" PVC. These are the same connectors that come in Sonostar Mega Dome and Mega Sphere kits. Typically, they are used at the base of a dome, but they can also be used in a doorway, where you remove struts for an opening and you want it to be flush, without the 6-way arms sticking out. Designed to fit either 1" or 1.5" Schedule 40 PVC.
Sonostar 4-Star Dome Connector Hubs are designed to be used with either 1" or 1 1/2" Schedule 40 PVC tubing. Since PVC pipe is measured by the inside diameter of the pipe, it should be noted that the outside diameter of the MegaHubs corresponds to the inside diameter of a 1 1/2" PVC pipe. The inside diameter of the Mega Hub geodesic dome connector corresponds to the outside diameter of a 1" piece of PVC pipe. The hubs are dual purpose. Either a 1" pipe will fit snugly inside the hub arms, or a 1 1/2" pipe will fit snugly over the outside of the hub arms.
Each arm has exactly one inch of sleeve room for the inserted pipe. You have the option of either gluing the pipes into the hub connectors or securing them with nuts and bolts.