Cigarette Lighter Adapter- Cessna 172

I've been flying for 7 years now, and a few weeks ago I attempted to
plug in my portable GPS unit into a 2003 172 and ... I couldn't. The
"standard" cigarette adapter has been replaced with a smaller
something. I didn't have time to look too closely as to what the new
outlet is. The GPS was just a backup and I was just going locally .

If anyone else has experienced this, I would appreciate any info on
what adapter I would need to continue to use the "old" cigarette size
plug and who sells them.

Thanks in advance.