A very tidy 6 inch RIDGID adjustable spanner or wrench by the RIDGE TOOL COMPANY USA.

This wrench is actually 5¹/₂ inches long when fully closed.

Marked 'RIDGID PAT 1727623 6' on one side of the handle with 'RIDGE TOOL CO ELYRIA O USA' to the opposite side.

The patent was granted in 1929 and further details can be found here - https://patents.google.com/patent/US1727623

The adjustable top jaw is marked 'X 1/8 1/4 1/3 1/2 3/4' with the RIDGID trade mark on one side and 'B-2-1 OIL HARDENED 6' on the other.

There is also a faint 'F' cast into one side of the body underneath the lower jaw.

All parts move freely and tighten securely.