PROSOCOOL Pool track replacements are made of high quality materials. Improve the performance of your robotic pool cleaner and keep your Dolphin pool cleaner looking its best. Easy to replace old stretched and worn rails. Close fit, better traction, and increased work efficiency. PROSOCOOL Tracks are fitting With Dolphin Pool Cleaners Models: Apollo, Apollo Plus, Atlantis, Advantage Plus, Aquarius XL, DX3, DX4, DX6, C3, C4, C5, C6 Plus, Discovery (old), Endeavor, Enduro, Edge, Explorer , Liberty ,M200, M400, M500 ,M3, M4, M5, Maytronics Models from 2006 to Present Part PROSOCOOL Tracks are replacement for Dolphin Pool Cleaners Models: Nautilus (not all), Nautilus CC Plus, Neptune, Neptune Plus, Oasis Z5i, Premier , Primal X3, 3001, Prowler 820/830 , Pro ,Quest, Saturn (old), Sigma, OdysseyDX3S, DX4+S, DX5+S ,Triton/Triton Plus (old), Wave 50/65/75/90, X2 If it has been more than 2 years since you last replaced the track, check it for signs of wear, tear and compression. You'll find your automatic pool cleaner is working fine, but moving slowly, lacking traction on the pool floor and unable to climb walls, and PROSOCOOL Tracks are the solution. IMPROVE YOUR ROBOTIC POOL CLEANER'S PERFORMANCE - Worn out tracks cause several performance setbacks for your automatic pool cleaner. It may begin with sluggish movement, lack of traction on the pool floor, and inability to climb walls. Don't wait until the cleaner begins to malfunction. BR BR BR