Airtight and Leakproof: Two lines on the rim made a groove to fit tightly under the wire. Once firmly in place, you shouldn't be able to pull it out easily. Perfectly suitable for 6 liter pressure cooker: IP-DUO50, IP-DUO60, IP-LUX50, IP-LUX60, IP-LUX60V3, Smart-60, Ultra-6, IP-CSG60 and IP-CSG50.