Westinghouse 2 Pack Pagoda II Black Solar Post Cap Lights for 4 x 4 Wood Posts Interior base measures 3.88" x 3.88", rail adapter interior measures 3.5" x 3.5". Each light measures 5.94" x 5.94" x 4.75" Durable weather resistant construction will handle the outdoors with ease Patented Natural White LED Included with each light is a 600mAh Rechargeable AA Ni-Cd Battery Includes mounting base for installing onto a rail