This clock insert, like all clock inserts is a whole package in one. A clock insert includes everything you need to operate a clock. In one small package you get the clock movement, a case that neatly covers the movement, the clock dial enclosed in the case, a balck hour, minute and second hand, the bezel and lens, and a dial. Each of our 3 1/2" Clock Inserts are designed to press into a 3" hole. They are a friction fit clock insert that operates on a "AA" battery. To adjust the clock there is an adjustment knob on the back of the insert by the battery, simply turn the knob to adjust your time.