Secure spring cap with an elastic design provides a tight fit that prevents milk or syrup from leaking. Designed to preserve flavor and carbonation of craft milk beverages, ensuring a quality drinking experience when used with glass bottles and glass liquid containers. Leakproof spring mechanism creates a reliable seal, keeping contents fresh and securely contained. Versatile bottle tops for glass bottles and silicone glass bottle caps; suitable for small syrup bottles and other glass containers. Durable, foodgrade construction suitable for home, cafe, or kitchen use; compatible with standard glass bottle openings. Use scenarios Home storage of opened milk in a glass bottle: reseal quickly after pouring to maintain freshness and prevent leaks in the fridge or during transport. Flavor syrups and coffee additives: seal small syrup bottles to prevent spills and preserve flavor between uses or while traveling. Craft beverages and experiments: bottle tops for glass bottles to keep carbonation and taste intact during storage or transport in small batches. Specifications and compatibility Function: springloaded seal for leak prevention and freshness maintenance. Material: silicone and other bottlecap compatible components designed for glass bottles. Size and compatibility: designed for standard glass bottle openings and small syrup bottles (intended for common household and light commercial use). Performance: reliable leakproof seal with quick, tool resealing for everyday beverage storage and transport.