This disconnect is a safety on/off electrical switch mounted on the home near the condenser, heat pump or packaged unit. It is required by electrical code for safety and system servicing purposes.

The Alpine AG-DCT is a non-fused disconnect and is rated for up to 60 amps, but it is compatible with lower agerage systems as well. 

Disconnect boxes are typically paired with one or two electrical whips. 

(Please know that the one you receive may appear slightly different than the one shown in photo.)