Costco warehouses seemingly have everything from the popular $1.50 hot dog combo and affordable gasoline to gold bars and electronics.

While customers nationwide undoubtedly have their favorite product, the wholesale chain’s CEO said the most important item they sell can be found in a member’s pocket.

In an interview, Ron Vachris, Costco’s new CEO, told Fortune that the warehouse membership is the most important item they sell.

“Everything we do supports that transaction,” Vachris said.

Costco has a 130-million membership base, according to CNBC.

The company offers two memberships: the Gold Star for $60 and the Executive membership for $120. Both memberships grant customers access to the warehouse’s deals and promotions, but executive members also get a 2% cash-back bonus on each purchase.

Last year, Costco members were worried that the company could raise its membership fees, as they have done every few years, but company officials shut down those concerns.

“We haven’t needed to do it. We like providing extreme value. Certainly, while we have gone a little longer without an average increase, we feel we have driven more value to the membership,” Costco CFO Richard Galanti said during an earnings call in December.

Costco’s membership prices haven’t changed since 2017.

Non-members can sign up for a membership by visiting a Costco warehouse or signing up online.