The 5A/175G is an RF pentode with flying leads to the B8D base specification and for operation in the HF region. It is a direct equivalent to the CV4518. The blue writing indicates that this is also a VX7507.
The box it was supplied in was a plain cardboard box suggesting a professional use rather than a consumer product. No trace of the valve could be found in the Wireless World data books.
The bright structure is the beam plates (g3) the dark strips top and bottom of the image are the active parts of the anode and are formed from a single sheet that curves round the other side of the valve.
One side of the anode with the saddle on top connecting to the plate the other side. The two copper wires prominent below the lower mica are two of the cathode connections.
The thin glass tube envelope is 9 mm in diameter, and excluding the B8D base wires is 37 mm tall.
