If you're trying to replace foam pads on some other headset with Koss PORTABLE foam cushions, the following is mentioned: The cushion outer shape is a round disk, 1 7/8 inches in diameter and 3/8 inch thick. The opening in one of the disk's flat surfaces, that you stretch over your headset earpiece, is round and 1 1/4 inches in diameter. The space within the cushion that fits the outer diameter of your headset earpiece appears to be 1 5/8 inches diameter. I'd have known this product didn't match my needs if some other review had mentioned these dimensions, so there they are. They are very nice cushions if they're the size you need.