Heritage Farms has worked closely with the Purple Martin Conservation Association to develop these outstanding Purple Martin houses. Up to four "Quad Pods", each with four Purple Martin houses, can be stacked for up to 16 purple martin houses on one pole. Set includes easy to assemble quad pod of 4 nesting units and hub (shown with 2 Quad Pods stacked). Stack up to 4 quad pods, or 16 purple martin houses per pole. Each quad pod system comes with mounting hardware and instructions. Recommended basic system: 2 quad pods plus pole system. Pole system sold separately on this page:Pole for Quads. Simple design features snap-together parts. Assembles in minutes!