The 55-135mm f3.5 Canomatic R zoom lens is very uncommon. It was introduced in December 1963 and was very short-lived. Most 55-135 zooms I've encountered to date have shown lots of wear. This one is an exception.

A rather complex design with 15 elements in 10 groups, it was Canon's first attempt at a zoom lens. It has f/stops from f/3.5 to f/22 and focuses as close as 2 meters.

It is displayed here with its proper front & rear lens caps and fitted case.