Claim: Lumix has five types one of which is named Four Thirds.
Evidence: High-end
Ultra-Compact Ultra-Compact, Wide-angle Ultra-Compact High-end
Compact Compact, Wide-angle, Large Zoom Compact,
Medium Zoom Four Thirds Compact Bridge,
Ultra Zoom Micro Four Thirds Full Frame L-mount Waterproof, shockproof and dustproof One Inch sensor