This kit is in beautiful condition, both the lenses and the camera shows very minimal signs of use. New seals have been installed in the camera with a full CLA. The glass on the focusing mirror contains a light fog, nothing that will affect the photos taken on this camera. The glass on both of the lenses looks clean and great. Includes: Mamiya RB67 Pro SN: C25214 Mamiya-Sekor C f3.8 90mm SN: 140746 Mamiya-Sekor C f3.8 127mm SN: 80299 The first camera released was the RB67 Professional in 1970. The system comprises of a camera body, viewfinder, back adapter, film back, and lens. The camera body itself is quite simple and fully mechanical. It does not require any battery power. The shutter button is located on the front bottom right of the camera. It can be locked with a twist of the collar. The shutter is cocked manually by pressing down the large lever on the right-hand side of the body. The mirror within the camera and shutter in the lens are cocked at the same time. There are two focusing knobs on each side of the camera body similar to the Mamiya C series TLRs. The focusing screens are also interchangeable. The most common back adapter included in the system is the rotating back. The naming of the camera RB67 stood for Rotating Back 6 × 7.The RB67 was originally designed to supplement the Mamiya C series 6 × 6 TLR system and the multi-format Mamiya Press rangefinder camera system (6 × 4.5, 6 × 7, 6 × 9, others) but has surpassed them in popularity. Back adapters for using Mamiya Press roll film and instant film backs are also available. Due to its heavy weight (almost 2kg for the body alone) the RB67 is often said to be unsuitable for use hand-held use. This isn't necessarily true - with a decent neck strap the RB67 can easily be used on the move. The flexibility of the RB67 system made it one of the most popular studio cameras in the 1970s.The biggest difference between RB67 and RZ67 is that the RB67 is completely mechanical. The RZ67 has also mechanical coupling between the parts, but the shutter is electronic, and parts are able to transmit exposure information with electronic couplings. The first RB67 was introduced in 1970, and the RZ67 was introduced in 1982. The RB67 is a pound or two heavier than the RZ67. The RB67 is considered to be reliable in studios where the mechanical features are not bothersome, while the RZ67 does better in fast shooting applications. The RZ67 can take many of RB67 lenses, but this is not the case vice versa.