The Maximize ring set is a great product that I can only recommend. As for its intended use, it works exactly as advertised. It maximizes the size of exactly what you want. The specs/measurements of the cock rings are as follows:

Color: Black
Cock ring style: Stretchy ring
Max stretched diam.: Any size
Unstretched diameter: 1" / 3/4" / 7/8"
Length: 1 1/4"

My husband uses it to help extend and intensify our sex and it helps him to perform spectacularly. There is a difference between when he uses it and when he doesn't. The rings are fairly easy to put on (they stretch) and the different sizes are nice. The nubs on the cock rings are great for both of us. It is not something we use with other toys or things. You can use one or multiple rings depending on your mood for the day -- just make sure you don't leave them on too long (they can cause damage). The rings are odorless too.

This is a product you need to use condoms with if sharing with others.

We use warm water and mild soap to clean the cock rings. You can use a toy cleaner also. It is a product that's fairly easy to clean.

The cock rings can be used with silicone lubricants if needed.

They are Hypo-allergenic. They are also Latex free for those with allergies. The rings are also Phthalates free.

These are super easy to be discreet with (just don't leave them on the bathroom sink) and easy to travel with too. No issues with the TSA. :)

Best of all, these rings are spectacularly priced. If you have never used a cock ring before, these are the ones to get to start you off (and get you off - pun intended). You can't go wrong with these!