Will it hold a 40 oz Hydro Flask?

Yes. The adapter is rated for bottles from 18 to 40 oz with a diameter of 3 to 3.8 inches, which covers most 40 oz insulated bottles.

Does it fit my car's cup holder?

It fits cup holders with a diameter of 2.75 to 3.25 inches, which covers most cars. Measure yours first if it is square or unusually shaped.

Can I use it with a normal coffee cup?

Not well. The grip is sized for wide bottles, so slim cups and cans will sit loose unless you keep the rubber tabs in place and the cup is close to 3 inches wide.

Is $14.99 a good price?

It is the best new price tracked, at Amazon as of November 4, 2026, and sits at the low end of its recent range. With only two stores listing it new, there is little room to save more.

One black plastic expander adapter with four removable rubber tabs. No tools or mounting hardware are needed.

Where is the JOYTUTUS Car Cup Holder Expander Adapter cheapest?

At Amazon, for $14.99, as of our latest check.

Where can I buy the JOYTUTUS Car Cup Holder Expander Adapter?

2 stores we checked sell it, including eBay, Amazon.

JOYTUTUS Car Cup Holder Expander Adapter

Best price now

$14.99at AmazonObserved at 10:26 AM

Compared across 2 stores. Prices are checked against each store and labelled with when.

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Our take on the JOYTUTUS Car Cup Holder Expander Adapter

The JOYTUTUS Car Cup Holder Expander is a plastic adapter that drops into a standard car cup holder and widens it to grip bottles and large cups from 18 to 40 oz with a 3 to 3.8 inch diameter. Four removable rubber tabs adjust the grip, and the base fits cup holders 2.75 to 3.25 inches wide. At $14.99 at Amazon as of November 4, 2026, it sits at the low end of its recent range, with only two stores pricing it new.