Classy Caps FS100B Fairmont Postcap Solar Post Cap Light, 5" x 5", Black High performance solar lights stays lit for up to 10 hours Lights up automatically every night 2 high output led's for brilliant white light 1 long life AA rechargeable battery included Fits 3 Post Sizes! Will fit over an ACTUAL 5"x 5", 4"x 4" or 3.5"X 3.5" post For fence Posts and also has wall mount bracket included