The Sony TC-366 is a reel-to-reel tape recorder that was popular in the 1970s. It features three heads and is known for its robust construction and capability to handle 7-inch reels. The unit offers three speeds: 1-7/8, 3-3/4, and 7-1/2 inches per second, providing flexibility in recording quality and duration. It also includes features like an automatic shut-off, sound-on-sound capabilities, and the ability to both record and playback.