Our first probe is our Hot and Cold Hammer Probe. The hot and cold hammer probes can be used in conjunction with hydrating serums as well as restorative serums. The hot probe opens pores and stimulates collagen. The cold guide will shrink pores and calm and repair the skin. Select the hot and cold hammer to click into, you can adjust its temperature from low to high. 12 is hot guide,-1-2 is cold guide. The operation time is about 10 minutes.