Small institutional twin wheel caster. Made for light duty usage, the quality of the caster is quite acceptable. Smooth cover, the PP plastic is made thick and firm and very easy to roll. Can be used as spare parts for rolling chairs.
Solution to minimize overall height and maximize load capacity. Dual wheel casters also improve stability and swivel more easily than wider-face single wheels. However, this 40mm diameter caster is the most "ugly" one of the Series.