ANTI SCRATCH MATERIAL Discovery Trolly Luggage with Scale to meausre the weight and tracker chip to find the bag within 100m. Material's light and durable ABS. wheels're 4 turn 360 degree wheels. Trolly's Outside alluminum alloy trolly. Lining's 120D. Lock's combination lock + bluetooth . Sizes: 20 and 24 and 28 inch wheels.