The description :

Available as a set of four plyo boxes, 15cm, 30cm, 45cm and 60cm in height
Commercial grade product for plyometric training, cross training, and functional training.
All foam construction. Extra-rigid urethane core and softer laminated polyethylene foam on the outside.
30 oz. Mildew and UV resistant expanded vinyl with non-slip landing area. Hook and loop fasteners.
Footprint: cm x cm. Unit weight in height:
15cm – 5.2kg (90cm*75cm*15cm)
30cm – 10.25kg (90cm*75cm*30cm)
45cm – 15.3kg (90cm*75cm*45cm)
60cm – 19.5kg (90cm*75cm*60cm)