Grado has changed from their original pad design - the "donut" design - to a design that covers the transducer - no donut hole - on some of their lower priced models - SR60i, SR80i, SR125i. The new design is called the S-pad. The new design cuts the highs a bit, which some users object to.
The L-pad, made for some more expensive Grado models, is a donut design, only thicker. It will work on the 60, 80, and 125 models. But for the perfectionist, there is a source that makes replacement pads to the original Grado spec for those models, now called the TTVJ Flat Pad. Here is the source.