The Hawkins Stainless Steel pressure cooker body and lid are made from food-grade, 18/8, non-magnetic, superior stainless steel (AISI Grade 304). The 18/8 superior stainless steel lid ensures the highest levels of hygiene and durability. The pressure cooker Body and Lid are made of food-grade, superior stainless steel for maximum hygiene and durability. On the outside bottom of the pressure cooker, sandwiched between two sheets of stainless steel, is a core of 4.1 mm thick aluminium, which spreads heat quickly and evenly. The unique Hawkins Pressure-Locked Safety lid ensures that when there is pressure inside the cooker, the lid is pressure-locked like a modern jetliner door. It cannot be opened until the pressure has fallen to a safe level. The fixed sturdy pivot assists the self-centralising lid in locking securely and safely in place, ensuring a steam-tight seal. It is also designed so that no undue pressure is put on the plastic handles, as it is part of the metal handle itself. Thus the handles last longer.