Pole Tenon Adaptor (Model# APTASUNV): Square adaptor allows installation of up to four fixtures. Fits 22 /3˝ vertical round tenon. Use with mounting arms with 2˝ or 33 /8˝ OC bolt patterns. Steel with textured bronze finish, includes stainless steel mounting hardware and polycarbonate cap. 4˝ x 4˝ x 10⅝˝.