1. Product Packages4x 6101611 Pool cleaner climbing rings, 2x 9985006 Pool cleaner timing track, 6x 3884997 Guide wheels pulley kits.2. Replacement Dolphin Pool Cleaner PartsThis pool cleaner parts are compatible with Dolphin Maytronics Nautilus M400 M500 DX3 DX4 DX5 DX5S DX6 Nautilus Deluxe 4/5 Triton Apollo Plus Wave 50 65 75 90 Discovery Quest Edge Prowler 820/830 M4 M5 C3 C4 C5 C6 Plus Evolution X5, Deluxe 3 4 5, Dolphin 2x2, Premier.3. PerformanceWorn out tracks will cause the performance of the automatic pool cleaner to deteriorate, which will result in slow movement, lack of traction on the pool floor and inability to climb the walls, and need to be replaced in time. They are important for maintaining the and proper operation of your pool.4. Quality9985006R2 Pool Crawler, 3884997R6 Guide wheels pulley kits and 6101611R4 Climbing Ring Replacement Parts are made of high quality materials to ensure a longer life. They are suitable for maintaining the and proper functioning of your pool.