Schwinn Airdyne AD3 Ergometer Display replacement battery cap, 3D-printed.These are 3D-printed plastic battery caps that fit the Airdyne AD3 Ergometer Display very nicely. I test the fit of each battery cap before shipment to make sure it fits correctly. You will receive 2 black battery caps made of tough PLA plastic which is stronger & twice the price than standard PLA plastic. You will also receive a maxell LR44 replacement battery.