Devices with “pigtail” leads have short, flexible wires. Terminating them requires tying them together to the existing wiring coming out of the wall and capping them with wire nuts to secure them together. Watch this Leviton video to learn how to wire a device using this method.
If you're ever unsure about wiring a device, please consult an electrician.
For more information on specific termination methods or wiring of Leviton devices, visit Leviton.com