Complex sentence: The Single 8 cartridge was designed to use the camera's film gate to hold the film in place during exposure, in contrast to the Kodak system which had a plastic pressure plate built into the cartridge.
Split into simpler sentences: The Single 8 cartridge was designed to use the camera's film gate to hold the film in place during exposure. This contrasted with the Kodak system which had a plastic pressure plate built into the cartridge.