Transtector
A Transector is a non-sentient Transformer body.
Japanese Headmasters Cartoon/Manga
Headless transectors are used by the small warrior Transformers of the planet Master to allow them to interact with and combat larger normal-sized Transformers. These small robots become Headmasters, transforming into the heads of larger non-sentient Transector bodies. They are able to switch Transectors at will, each combo resulting in different power levels and abillities.
Japanese Masterforce Cartoon/Manga
Later in the war, a group of Transectors, one of which was designed as a new body for the original Convoy, were intecepted by the Decepticons and ended up scattered. These were found and used by various humans on the planet Earth. These humans also become Headmasters or Godmasters, using special bracelets that let them join with and control their Transector bodies. In the end, these transectors somehow achieved sentience in their own right and left their partners behind to become independent, full-fledged Transformers.
