Complete Set: 6 Cobalt Blue Glass Roll on bottles with stainless steel roller balls, black caps, and 1 dropper included Versatile Use: Suitable for essential oils, perfume oils, or other liquids Safe and Secure Packaging: Provides safe, secure and convenient packaging for your liquids Travel-Friendly Design: Conveniently fits in your purse for easy portability UV Protection: Cobalt Blue Glass protects against harmful UV rays Stainless Steel Roller Balls: Durable stainless steel roller balls ensure smooth and consistent application Capacity and Measurement: Each bottle holds 10 ml of liquid with a 0.5 ml dropper for precise filling These high quality, Cobalt Blue Glass Roll-on bottles with stainless steel roller balls are perfect for use with essential oils, perfume oils, and other liquids. Snap in the roller-ball by gently placing the roller-ball in the bottle and then firmly tighten the cap until the roller-ball snaps in. Use the roll-on bottle to apply the perfect amount of product each time. Remove the roller-ball by applying pressure with the cap. The beautiful, Cobalt Blue glass provides protection from potentially harmful light and the convenient size makes it perfect for travel.