Here's a clear NOS 175W Philips USA mercury vapour lamp.
Manufacture date: July 1996
Base: Mogul E39 Brass
Lamp shape: ED28
Made in: USA
Lamp life: 24000 hours
Ballast: H39
I recently was given a 400w Philips MH lamp with this sleeve design that was manufactured April 25, 2005. I like how Westinghouse (and later Philips) put the actual date on the sleeves of their MH and MV lamps..
yeah i like the date on the sleeve too, but westie never did that IIRC. Phillips-westinghouse lamps had it but not true westies i don't think since my westie HPS lamp from 1980 doesn't have the date, unless they didn't mark the HPS lamps for some reason.