The Sapphire Glue for Eyelash Extensions is carefully tested to ensure the highest quality and safety standards available for eyelash extensions. The Sapphire glue is recommended when working with a very low humidity levels in your work place but also such as in winter when we use a lot of heating. This eyelash extension glue is to be used by trained professionals only. It offers a superior bonding performance of 2 seconds and holds on for around 4 weeks before a refill is needed. It complies with all Health Canada regulations. It's ideal humidity level is around 30% for the best results.