I just got a single specimen of an Osram XP-24; it is a miniature foil filled bulb with a bayonet base, about 2 1/2" long overall and 1" in diameter. I do not see it listed on the Cress photo site. Is it uncommon? I did not know foil filled bulbs were made this small.

While I don't have first hand experience, i't my belief that the US market was filled byGE Wabash an Sylvania, but these big three staye out of the European market. Hence anything Osram over hear is at least scarce.

Mr. Cress does have one Osram "tubular-foil filled bayonet based lamp", different letters though. I'ts listed at $65.00