Insulation type: Double wall; Temperature retention: Yes (Keeps liquid hot/cold upto 12 hrs); Leak proof: Yes Best Usage: Gym, Sports, School, Outdoors Warranty: 1 year; Not covered in warranty: The warranty does not cover damages resulting from accidents, mishandling or tampering with the mechanism. Fabricated inside and outside in 18/8 quality stainless steel; its tough and durable.