Hydrometer is to measure the humidity and temperature and is a very useful device for eyelash extension. Thank to this, you know your current working environment and how it will affect your adhesive. The lower the humidity is, the slower your glue curing is. The higher the humidity is, the faster your glue curing.
Use this hydrometer, put it in your room and check it daily to choose the right glue for your clients.
Battery Operation: Require 1 x AAA battery (excluded)