I installed this clock outdoors on a wood board fence 1 week ago. It has a circular base which is detached by rotating the clock. There are 2 mounting holes on the base which are recessed inside narrow triangular spaces, so it took a bit of care to hold screws in them and fasten to the wood. The holes are small, requiring thin sheet-metal screws, like no. 6. The clock does not come with mounting screws. So far it has kept perfect time and has already withstood several rainstorms to no ill effect. It has a beautiful appearance, with a blue frame that matches the sky and nicely designed hands.