This easy to install GE 24-Hour Indoor/Outdoor Heavy Duty Mechanical Time Switch is ideal for use with fans, pumps, pool heaters, air conditioning and more. Its heavy-duty, metal construction and lockable, tamper-resistant metal case make this timer durable. The Time Switch is easy to install with its 1/2 and 3/4 " knockouts, and simple to set. It includes a manual override switch. We recommend that this product be installed by a licensed electrician.