Pull-ring zipper shirts:

These were popular circa '71 - '73. I had one just about the time Maureen was modeling hers (although hers seems to be more like a sweater). Even though they were kind of popular and alot of people had them, it's almost impossible to find a picture of them on the internet these days. Mine was a long sleeve navy blue shirt with white bicycles printed all over it. Yeah, it was awesome...