a yellow plastic cover with a clear window. Top of the cover is the RAAF insinia and under this reads Royal Australian Air Force and Engineering Publication. Through the window on yellow paper are the details of the manual in black ink. There is also an amendment loose in the manual. The manual is held together with a long metal slide.royal australian airforce - manuals, australian air publication, engineering publication, overvoltage protector pn 1623-6-a

A cream coloured copied manual with black writing on it. At the top of the manual is a metal staple.royal australian airforce - manuals, overvoltage protector pn 1623-6-a