MSS12Previously known as the Grandpa Model, this 12-compartment, aluminum martin house system has many good management features. It has individual flip-up compartment doors, porch railings, dry-nest subfloors, a roof perch, door stops, a safety lanyard lock, and a 14 ft. sectional steel pole (included) with a rope and pulley system for easy raising and lowering. Assembly required.mss-12