The Stanley Aerolight™ Transit Mug | 0.35L Shale Metallic is a stylish, lightweight option to accompany your daily travels. With a 4-hour hot & 6-hour cold insulation capacity, this leakproof mug with locking lid can keep up with your active lifestyle. Plus, BPA-free construction and dishwasher safe make for easy cleaning. At 33% lighter than Stanley’s steel tumblers, you’ll stay hydrated without the extra weight.