Leak-proof and airtight seal: The integrated silicone gasket creates a secure, leak-proof seal. To use, screw the lid onto the jar and press the flip cap firmly for a reliable seal. The airtight seal helps keep foods and liquids fresh. Easy pour: The flip cap stays open and out of the way when pouring or drinking, so it will not flop back into the stream. The cap is securely attached and will not flip down without deliberate force. Safe and durable: Ergonomically designed thickened handle built from high-quality, food-grade, BPA-free material. It can support the weight of a full jar without bending and is comfortable to hold and use. Reusable 4 pack lids set: Reusable canning lids compatible with wide and regular mouth Ball and Kerr jars. Replace plastic water bottles and disposable to-go containers by using them on mason jars or other bottles and jars. To drink, place a straw through the lid and convert it into a drinking lid. Use scenarios: - Home storage and serving: store sauces, oils, coffee, juice, or leftovers in mason jars with a secure, leak-proof seal and easy pouring. - Meal prep and daily use: prep and portion soups, smoothies, or dry goods in jars and pour without hassle at mealtime. - On the go replacement for disposable bottles: convert jars into reusable drink containers for water or beverages, with the option to insert a straw for drinking. What you get: 4 reusable lids compatible with wide and regular mouth Ball and Kerr jars. Made to replace disposable containers, with a secure leak-proof seal and easy-pour functionality.