I've been riding clipless for about a month, pedals are SPD m505. I picked up a couple of extra pairs of shoes on ebay, a pair of specialized and a pair of lakes. Both pair came with cleats. This evening I put on the lakes to ride, clipped in and took off. They actually clipped in easier than the cleats that came with my pedals. I'm riding along, it's pretty out, I hit the first traffic light just right and get about a mile and a half from home. I'm rolling toward a 4 way stop which is VERY busy this time of day, approaching on a down hill. I start to brake and realize I can't clip out. I try waggling both feet around every which way and nothing works. Traffic is heavy and I'm desperate.

I look ahead and there is a large grassy area ahead I can ride down a hill to, off the side of the road, provided I can get through the intersection. I manage all of that, coast down the hill and flop over into the soft grass. Whew! I have to take my shoes off and rip them off the pedals. Then I put them back on and rode home with the pedals in my arches so I wouldn't accidentally clip in.

The cleat that was hung looks like this:


Regular cleat:


There are some small differences. What kind of cleat is the first one? How many different kinds are there? I think both are Shimano.

TIA,