Timer description matched the product exactly. The instructions list three different models of this timer switch. The difference between models only appears to be how the wires connect. The timer came with two screws to mount to the electric box, and two screws to make the wire connections. It also came with the timer plate and nut to fasten the plate, and the knob. Wire connections were easy, although you have to look closely to see the molded in "line" and "load" markings. Basically its black wire feed to the line connection, then the fan (or other device) to the load connection. Make neutral to neutral (white) and ground to ground (bare copper) connections as typical of any wall switch. And like the description says, "Supplied with a molded white time dial plate designed to fit either toggle or decorator style switch plates ". That means it only comes with the timer plate, but not a switch plate. (the time dial plate is the rectangle with the time marks on it. It fits a standard wall plate with large rectangular opening).It works as it supposed to and seems accurate with its timeing. The knob was quite hard to turn the first time, but after a few days of use it has loosened up in both directions. The clicking noise of the timer can't be heard over the sound of the whole house fan that is directly overhead. With the power off, I noticed the timer is quiet enough to use with bedroom ceiling fans (which I am considering doing).All in all, its appears to be a good buy. Much less expensive than the choices at the home centers, and at 6 hour timing it is just what we needed for our attic fan.Update: The Master Flow whole house attic fan came with a rocker switch with Off, Low, and High positions. When the fan was installed, I put in a two gang electric box (double box) because I knew I wanted to add a timer. But now with this timer installed, the rocker switch Off position was no longer needed, plus finding a cover plate with the decorator opening on one side for the time, and a custom size hole for a rocker switch on the other was impossible. So I tossed the rocker and got a regular 3-way wall switch, and wall plate with the regular toggle switch opening on one side, and the decorator opening on the other. Then I wired the power to the timer, then to the 3-way. So now the timer functions as the on/off switch, and the 3-way toggle is just High and Low. Much better functionality, and nice clean wall switch plate.The whole house fan I have is a 30" belt drive model that is rated at 4 amps, so this switch is more than sufficient.BTW, the timer switch specs/ratings are:Resistive: 20 Amp, 125 VAC, 50/60 Hz10 Amp, 250 VAC, 50/60 Hz10 Amp, 277 VAC, 50/60 HzTungsten: 7 Amp, 125 VACMotor: 1 HP, 120 VAC, 50/60 Hz2 HP, 240 VAC, 50/60 HzOperating Temperature: -40¢ªF to 104¢ªF (-40¢ªC to 40¢ªC)Style: Can be used with decorator and toggletype switch platesDimensions: 2.79" H x 1.6" W x 1.19" D