Classy Caps SL079W Pvc Prestige Solar Post Cap, 4" x 4", White High performance solar lights stays lit for up to 12 hours Lights up automatically every night auto off switch 2 high output led's for brilliant white light 2 long life AA rechargeable batteries included Will fit over an ACTUAL 4"x4" PVC or nominal 4" x 4" wood or 3.5" x3.5" post ( includes 3.5"X 3.5" adaptor)