Spiral Thermosteel Bottle (Milton)Leak Proof: Yes; Retain temperature: Yes; Double walled Vacuum insulated technology keeps beverages hot or cold for 24 hours. Inner copper coating for better temperature retention. This Product Is Under 1 Year Warranty From The Date Of Retail Purchase Against Any Manufacturing Defects In Material And Workmanship. The Warranty Does Not Cover Damages Resulting From Accidents, Mishandling Or Tampering With The Mechanism. Warranty Valid Against Producing