Thorn MBIF/H 400w Halide lamp

This was listed on Ebay recently along with two other high wattage incandescent lamps (identical ones are already featured in my gallery), although I managed to get the lot very cheap and I only really wanted this lamp. With it being listed as used it was a bit of a gamble whether it was heavily used or EOL, but after it arrived and after cleaning it it appears to have a clear arc tube! This still has the old Thorn lettering and is quite an early metal halide lamp.