This platen's width is 4 inches. It's my understanding that the length is supposed to be measured along along the outer curve of the foam. That measurement is 8.5 inches, so I believe this is closest to Stahl's largest size. They call it a Champ, and it is advertised at 4 x 8 inches. At time of listing, I have some other sizes as well. Please check my other listings if you need them.
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