For a while, a lot of people thought physical credit cards would become obsolete and that payment apps and smart devices would make it so that consumers never had to swipe their plastic in public again. So naturally, the metal credit card craze caught industry observers by surprise. For credit card users, many of whom fall in the millennial age bracket, security and privacy take a back seat to the look and feel of a sleek, beautifully designed metal credit card. So what else besides looks makes these high-end credit cards must-haves for consumers?

Most metal credit cards are travel rewards cards, and in many cases, their benefits are as seductive as their appearance. As the granddaddy of metal cards, the eye-catching American Express Centurion credit card, an invitation-only product, comes with a jaw-dropping, sign-on fee of $7,500 and an annual fee of $2,500. So if you’re lucky enough to snag one of these credit cards, popularly known as the black card, you’ll shell out $10,000 the first year you have it. Cardholders have to spend $250,000 annually to remain in good standing, but the card offers first-class travel benefits including upgrades on Delta Airlines, Gold Guest Status at Starwood Hotels and Resorts, and a $500 credit for booking a cruise with select companies.

The Chase Sapphire Reserve Card, one of the most popular metal cards around, offers rewards that some might describe as amazing. Cardholders get 50,000 points for spending $4,000 over the first three months. Points can add up to significant savings on flights and hotel says, depending on where and how cardholders use them. At $450, the Sapphire Reserve Card’s is fairly steep, but Chase offers a $300 credit, so users end up paying about $150. No blackout dates and access to more than 900 airport lounges round out the top perks Chase’s leading credit card has to offer. The card is so highly sought after that when the company temporarily ran out in late 2016, it had spent almost no money on advertising; buzz about the card spread online on its own.

US Bank’s Altitude Reserve credit card, a relative newcomer in the world of metal credit cards, has travel perks similar to the ones offered by Chase’s Sapphire Reserve Card. The card has an annual fee of $400 and offers a travel credit of $325 to offset the cost. Cardholders get 50,000 points that can be used for travel for spending $4,500 in the first three months. Though not as flexible as the Sapphire Reserve Card regarding how points can be redeemed, cardholders can save on travel booked through US Bank’s portal.

Design has a lot to do with the popularity of metal credit cards, too. Today, most credit cards feature minimal designs and metal credit cards are no different. Some credit card companies make the cards from proprietary metal blends, while others publicize the type of metal used to make the cards, adding to their allure. Companies that offer metal credit cards are looking to impress consumers and don’t mind spending up to 20 times more than it costs to produce plastic credit cards to attract them. With so many reasons to jump on the metal credit card bandwagon, as a consumer, it’s a good idea to keep cost in mind even when you find the card visually appealing enough to apply for one. If you do all of your spending on credit cards and use travel rewards frequently, definitely apply, but you could be wasting your money if you’re conservative with your credit card spending. Keep the weight of metal cards in mind as well. The cards are heavy and can weigh down your wallet or handbag. Also, some stores may have difficulty swiping metal cards depending on the type of equipment they have.