This purple martin house is constructed with aluminum, which is best suited for the purple martin. It is cooler than plastic. The Starling Resistant Entrance Hole (SREH) is a tried and proven method for helping to eliminate the pesky European Starling. This hole is cut to an exact height restricting starling entry but allowing safe entry for the purple martin. This house has 16 - 6"L x 6"W x 5.125"H rooms. House comes factory assembled with rivets. Description * Made in the USA * 4 floor/16 room house * Comes factory assembled with rivets * SREH - Starling Resistant Entrance Holes (Crescent shaped) * All aluminum and stainless steel exterior is strong and able to withstand weather * Lightweight for easy raising and lowering * Ventilated roof keeps birds cooler * Hinged doors for ease of cleaning * Guard rails to protect the young * Porch dividers prevent male porch domination * Reflective roof attracts purple martins Details UPC 789453820075 SIZE 14"L x 19"W x 26"H Each room is 6"L x 6"W x 5.