Below functions for robot vacuum cleaner SQ-D5501 for your refer first
1,​ Two​ side​ brush​ and​ 2​ main​ brush.​ It​ is​ easier​ cleaning.​
2,​ Lithium​ ion​ battery​ 1800MAH
3,​ Big​ Mop​ with water tank 180ML. Better for second​ cleaning
4,​ 100%​ Anti​ falling​ function
5, 100% Anti​ impact​ in​ the​ front
6,​ Big​ dustbin​ capacity​ 0.4L
7,​ Very​ lower​ noise​ less​ then​ 45db, Ultra-quiet
8,​ Working​ time​ is about 75 minutes
9,​ Auto​ recharge​ base
10, Three Step Suction Power, Suction power can be adjusted to strong.
11, LED display & Touch Screen
12, Error Codes Display: Can help to identify abnormal situations automatically.
13, With virtual wall: The cleaner will not enter into off-limit area.
14,​ Double Cleaning Modes: The cleaner is equipped with one
     suction nozzle & one main brush. Users can exchange between
     suction nozzle and main brush conveniently according to their
     different requirements.
15, Using suction nozzle, can help to solve the problem of hairs wrapped
      around the main brush more efficently.
16, Various cleaning modes: auto cleaning, spot cleaning, scheduling
      cleaning and edge cleaning mode.  
17, Air Purification Function: Can purify the air in localized area.  
18, 2.4GHz Bluetooth remote controller with rocker buttons: Users don't need
      to point it at the cleaner to operate and can use it more easily.
19, Powerful Suction: Using aluminum fan blades & professional motor, up to
10, 000rpm, can pick up fine dust and hairs on floor more efficiently.

Detail Pictures show: