Review on 🚗 Universal Vehicle Cup Holder Mount Adapter with 3.5” 90mm Suction Mount Surface and Adjustable Base for Standard GPS Mounts & More - Holds Smartphones (iPhone, Galaxy S21), Tablets, Radar Detectors, MP3 Players, and More (Compatible with Existing Suction Mounts) - Includes Free ChargerCity Micro SD Card Reader by Carrie Johnson

I just received my order and the base of the cup holder is exactly like the picture and I really didn't know exactly how it would fit as my cup holder hole has one 3.5 inch diameter. the top, but the way they narrow the top of this insert fits my cup holder perfectly, and when you rotate the top counter-clockwise, the "arms" spread out to fit the inside of the car's cup holder to grip to give it stability and this is great for attaching my phone holder to the suction cup. This product is obviously plastic, but it feels comfortably smooth as you twist the top to tighten it in the cup holder. I am very happy with my purchase and so glad I found this item. I personally think it's a bit overpriced, but it works well and they say you get what you pay for. I couldn't have done something like this cheaper (which I intended to do), especially considering how long it would take, so overall a really fair deal. I would recommend it to anyone who needs to attach a phone holder to a cup holder.