Aquabot X4 Awarded "Best Value Robot" based on rich feature set combined with the low price - 360 Anti-Tangle Swivel + Oversized 190 Cubic Inch Top-Loading Cartrdge + Free Transport Caddy + 3 Year Warranty Ideal for all pool shapes (above ground and inground) up to 60 feet. Highly energy efficient - each cleaning costs about 5. Industry-leading pumps circulate 85 GPM for a cleaner pool with fewer chemicals. AutoX Pool Mapping calculates the pool shape and the best cleaning cycle for speed and efficiency 4WD traction and micro-brushes ensure total cleaning coverage even on walls