dolphin sigma robotic pool cleaner with bluetooth and massive top-load cartridge filters, ideal for pools up to 50 feet. dolphin the dolphin sigma robotic pool cleaner: the laws of physics. reinterpreted. smartnav 3.0: advanced navigation and scanning software ensure your pool is cleaned using the most efficient route. no more watching your robot wander aimlessly questioning if it will ever pick up those leaves. tangle-free swivel: patented swivel with 360-degree rotation allow sigma to clean with ease without tangling. full wall and waterline cleaning: designed to clean floor, walls, and waterline with precision. powerful motors: 24- volt dc motors require 87% less energy than cleaners with ac motors. independent tracks: maintains constant grip when climbing slippery surfaces. moves smoothly over obstacles like drains. massive dual top-load cartridges: large, easy and convenient filter cartridges- forget messy, cumbersome bags. powerclean dual scrubbing split brushes, attacks bacteria, algae, and biofilm for healthier water. drive by bluetooth remote control: download iphone/android app and spot clean from your phone! weekly scheduler: run automatically as you want- daily, 2x per week, or 3x per week. keeps your pool clean and ready to enjoy. quality assurance: 3 years