These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)

Brand may vary but all battery brands are verified to have the same nominal voltage of 3.0V and nominal capacity of 40mAh

I’m a Return and Refund policy. I’m a great place to let your customers know what to do in case they are dissatisfied with their purchase. Having a straightforward refund or exchange policy is a great way to build trust and reassure your customers that they can buy with confidence.