Stainless Steel Outer And Inner With Silicone Base Sleeve. Powder Coated Finish On Stainless Steel Material. BevGuard™ Insulation For Keeping Your Drink Cold For 24+ Hours And Hot For 6+ Hours. Screw On, BevLock™ Spill-Resistant Lid With MagFlip™ Technology To Keep Your Lid Open While You Sip. 100% Leakproof When Locked. Easy On & Off OctaLock™ Threading System With 8 Different Drinking Positions. Durable And Removable Silicone Base Sleeve Protects Against Drops, Dents And Dings . Cup Holder Friendly. Non-Slip Base . No Condensation . No Metallic Taste . Meets FDA Requirements . BPA Free. Hand Wash Recommended.