iRobot Roomba 4150 Silver Robotic Vacuum Cleaner for $144.99 shipped after promo code EMCLXMW33. Here is a sceeenshot for your reference. It features dirt detect, stair avoidance system, surface transitioning, bag less debris bin, and advance power supply battery. It can be fully charged in 7 hours. This iRobot usually sells for over $179 and more.