THE FOLLOWING SIGNS ARE 637x883 PIXELS EXCEPT FOR THE LAST TWO WHICH ARE 419x554 PIXELS.

Click on the thumbnail for a bigger image. 

Very common sign used in letting drivers know that you're going to slow down.

This sign means that you will slow down quite a bit, for example, from 75 down to 25 in just one jump. I haven't seen this sign used in Arizona.