Yes-- it should be the same as the dash lights, the sub-miniature base # 2721.

 

Thanks for the quick reply I'm going to call them today and order a box

 

To clarify (and if memory serves) its not the same as the dash lights. The dash lights are are an all-glass bulb that pop into a plastic twist holder in the dash.

I believe the clock bulb uses a panel-mount bulb, which has the bulb integrated into a one-piece assembly with a twist holder. It looks like that's what you're buying with the 2721MF: it has a 2721 bulb in a B8.5D base (panel mount, I assume 8.5mm hole size).

I can't tell you if the 2721MF is the same size as the one in the clock, however. It looks like it but I can't tell for sure.

 

what clock ar we talking about here?

the analogue (tick-tock with old fashioned hands!) S4 clock or the green display Borg clock?

The S4 has two bulbs it seems:
http://www.alfabb.com/bb/forums/1193010-post3.html

the digital clock (LCD) single bulb is discussed here and looks very much like what Tom above illustrates.
http://www.alfabb.com/bb/forums/940039-post10.html

whether they are actually the same bulbs I dunno....look to be from the back view of both clocks......never had the bulb/s out of my S4 clock to actually compare!

 

The bulb is the 2721, the smallest of the series I believe, rated 1.2 watts. It is not commonly found at auto parts stores, either, at least around here. There is another T 1-3/4 series bulb that is just slightly larger, a bit higher wattage, that won't fit the socket Gubi refers to. I know that because we bought a supply of the wrong bulbs for my son's GTV-6, and it turned out only the 2721 would fit the sockets correctly in the instruments. The wrong bulb actually expanded the socket slightly to the point where it would not fit into the base of the instrument, which is where our suspicions began.

Anyway... back to the clock. I hope you get the correct bulb, I was talking about the analog clock such as the one in my 1991 Spider.