Inside Diameter: 1.89 inches Outside Diameter: 3.62 inches Thickness: 1.02 inches Our replacements are made from heavy duty Material ; ensure to last longer. They are perfect for maintaining your pool safe and functioning properly. Fit the following Robotic for Dolphin Pool Cleaners: M200,M400,M500,DX3,DX4,DX6Nautilus, For Nautilus CC Plus;Aquarius XLPremier Oasis Z5i,For SigmaSaturn (old)Deluxe 4/5, For Triton (old)Atlantis, For ApolloApollo Plus Wave 65 Endeavor/For Edge HD30012X2,For Wave 2X2 Prowler 820/83 When your Cleaner continued to work, The climbing ring will be abrasion. At this time, It is recommended that you replace it with new a set climbing rings. Installing this takes about 30 minutes. You need to take apart the whole robot. Not hard but you need to be methodical and avoid breaking plastic parts. Perfect Fit : 1. At the beginning of the pool season,if your pool cleaner stops climbing the wall,or keeps getting stuck. 2. At this time, you will need our climbing ring, which will perfectly fit your Dophin rock climbing equipment. 3. After replacing it with a new one, it will move up and down on the wall, climb up the steps,and the cleaning effect will also be improved. 4. Give your pool a new look and give you a different feel, therefore , so it will be the perfect choice for you. We offer two essential Parts for MAYTRONICS Dolphin Pool Cleaners： Climbing Rings Timing Track