1. The outlet valve is made of unique silicone material,can up to 1.6ml/dose. 2. There are two types of bottles fillable and disposable.(Factory standard inner bottle). 3. The mechanical principle design of the product is simple.Press the surface tightly and the liquid flows out. 4. The two plastic rods at the bottom of the product are special hard materials that replace the original metal spring, and will not rust or damage. 5. A whole face shell can be printed. 6. Logo and color can be customized.