Isosteel VA-9572 Auto-Insulated 0.4 L of double-walled 18/8 stainless steel incl. Plastic screw cap with sealable drinking spout and anti-slip floor (household goods)
For nearly 3 years, this mug is a faithful companion. It is easy to clean, is absolutely tight, so can therefore also be transported in bags, etc. and maintains reasonably warm. (In winter in extreme sub-zero temperatures, it will not happen so long)