Ever have your iced coffee ruined by melted ice, your favorite fizzy adult beverage turned not-so-cold by a poorly insulated mug? Then check out the Flet tumbler. 

Flet claims to be a one-of-a-kind tumbler that maintains freshness and original taste in juices, beers, sodas: you name it. The secret is what’s called the “FLET stick,” a stainless steel stick designed to keep your drinks cool. Pop the stick in the freezer for anywhere from four to eight hours, place it inside the tumbler, and it will magnetically attach to the bottom and keep your drink cold all day long. Without the chilling stick, the tumbler can keep drinks hot for up to five hours, too. 

The tumbler is tough as hell and sustainable, too. Each is made from durable food-grade stainless steel sourced from post-consumer recycled steel and is dishwasher-safe. The non-metal parts, such as the silicone bottom, lid and straw, are made from BPA-free, environment-friendly materials. 

Flet tumblers are available for order on Kickstarter. For more information, visit their official website, Facebook page or Instagram.