Kefir Fermenter: Set of Strainer Lid (Regular Size for Mason/ball Jars) and Container for Kefir Grains (Small Size - For 0.3 L-0.5l Volume) Use any mason jar you have. Add grains in container. Place container with kefir grains inside jar and pour milk. Kefir will be ready in 20-24 hours. Lid with screen protect your fermentation from insects and support aerobic conditions for grains. Removable screen has hundreds of tiny holes. Diameter - 0.7mm. Set strongly simplify method for kefir preparation because exclude use of strainer and pouring from one jar to another. Type KEFIR FERMENTER to see other devices related to home kefir with or with out kefir grains