Each bottle is made from high impact glass, The glass is thin but durable and not easily susceptible to leaking, scratches, or breaking.<br> So that it could safely stores various substances without damage.<br> These to-go bottles are designed with holding essential oils, perfumes and fragrances, facial and body mists, and various water-based liquids in mind. It is perfect cosmetic accessory for your daily activities and extended travels.<br> How to use it:<br> The bottles come with separate roller/stopper and screw caps. To assemble, simply insert one roller/stopper into the glass bottle after filling and press the stopper down carefully (not pressing directly on the metal ball) until it sits tight. Then screw on the cap.