2 Pk Solar WHITE Post Deck Cap Square Fence Lights 5 LEDs Operating Time: Up to 10 hours (depending on the regions, weather and sunlight availability) Overall dimensions : 5.4" (L) X 5.4" (W) X 3.5" (H) Two Mounting Bases (Inside Diameter) : 3.75 "X 3.75" OR 4 1/16" X 4 1/16" (PLEASE GIVE US YOUR SIZE) Fits on all PVC/Vinyl/Plastic/Composite and Wooden 4"x4"Posts & Deck Rails (Posts Measured Side To Side 4" or Less) Automatic on at dusk, off at dawn (on/off manual override switch)