These are NTC 3950 100K Thermistors that can be used for bed temperature measurement. You get 2 thermistors in this package, the thermistor portion is about 120mm long and the flying leads side is about 900mm long. If you need glue to secure these in your cast bed plate, we also have RTV silicone for sale.
Here is a guide on how to install a thermistor in the thermistor slot of our beds. Guide Here