please note. W130 and W140 are upgrade brushless motor. but only W140 support water spay function. choose the one you like Description 1,Intelligent cleaning routes, Clean your high-rise windows in a safe and easier way; Offers you a new way of window cleaning; W130 /W140 square robot window cleaner with stylish design and good performance; 2,Easy Operation: Control your robot in three simple ways: One touch Key- Remote. AI Smart Cleaning Modes: Multiple smart modes: in patterns of Z, N, or Z- to- N ,more than efficient , more than you expected. N mode : Spray water on the lower side only ( NO Spray water on the upper side ) Z mode :Spray water on the Both side 3,Square Shape Covers More: W130/W140 Covers maximumly 99% of the glass surface; Back to where it start when finished the work; 4,designed Mico Fabric Cloth with no hurt to glass surface; Available to frame and frameless glass,tables,and smooth floors/wall surfaces. 5, Multi-levels of Safety Guarantee: Multi-direction anti-falling sensors,with strong safety rope equipped; The built-in UPS battery help robot suck on windows for 30minutes and send alarms if power supply is cut suddenly; Multi-condition Application: use W130/W140 to clean internal/external windows of high-rise buildings/stores bathroom windows, or other flat surface like marble walls, ceramic walls.