The three interchangeable earcup pads make the c-Jays unique from other on-ear headphones. In addition to small, medium, and large sizes, the pads are made from three different foam densities that get thicker with each size.
The smallest pads are made of the thinnest amount of foam that allows for the most sound to penetrate through the membrane, so this pair is ideal if you're looking for the most bass and treble. At the same time, the thin pads also allow for the most direct contact with the hardware underneath, so you might need to take a break or adjust the headphones on your ears every half hour or so. Still, these are our favorite pads to use in terms of audio fidelity--you get an even balance of rich treble and bass support, although their exposed design means anyone in close proximity will hear what you're listening to.
The medium pads are the closest in density to the stock Sony Walkman headphone covers we mentioned earlier (if you're old enough to understand the comparison) and still allow an adequate amount of sound to sift through, although the muffled sound clarity is palpable at this size. These are also the most acceptable compromise between sound quality and comfort over long listening sessions, so they earn our recommendation if you plan to use the c-Jays over a full day of work. Alternatively, we like the smaller size better for quick listening sessions over errands or in between classes.
The largest diameter cushion is the thickest and changes the headphones from an open design into a circumaural set that fully cover your ears, but the sacrifice in sound quality isn't worth the comfort. Bass thumps are practically inaudible, and the oversize padding barely allows any instrumental distinction through its barrier. Whichever size you choose, Jays makes it easy to slip the pads up around the speakers for simple experimentation before you make a decision.