These are temperature sensors for Creatbot 3D Printer hot ends.
There are two types for these printers. Please ensure you choose the correct version.
The original is a Thermistor style for the teflon lined hot ends.
The second is a high temperature "K" style Thermocouple for the all metal hot end 3d printers.
This image is of the orginal thermistor style temperature sensor for Creatbot 3d printers