If you received additional Sensor Dots or 4-wire Cradles to use with your Byteflies Kit, please review the relevant information here and here. There are no differences between these Sensor Dots and 4-wire Cradles compared to the ones that are included as part of your Byteflies Kit.
Sensor Dots and 4-wire Cradles are not standalone medical devices. They can only be used as an accessory to a Byteflies Kit (Model 1). All the same safety precautions apply.