The discs are 25mm in diameter and 3mm thick. As they are of a flat profile (not domed) they are brilliant for placing between loudspeakers and stands to prevent vibration being transmitted to the stand - which can colour the sound dramatically - without allowing too much 'rocking' movement from front to back. They are also excellent for placing on the plastic feet of electronic components all of which will benefit from isolation. Sorbothane has a slightly 'sticky' feel to it and the discs will happily cling to most flat surfaces so you can use them wherever you feel isolation is required.