Fostex Replacement Ear Pads model number:
These pads were designed for the T20RPmk3, T40RPmk3 and T50RPmk3 headphones.
NOTE:I have been able to fit these pads to the T20RPmk2, T40RPmk2 and T50RPmk2 models, and several buyers have as well. Folding them inside out helps, and I've posted pictures of the process. HOWEVER, it's a tight fit, and not everyone has been happy with it. Please be aware of that if you're buying these for the mk2 models.