Model CT3303 is fitted with 4 non marking swivel castors and comes complete with 3 containers.Model CT3305 is fitted with 4 x non marking swivel castors and is available either complete with 5 containers or as a trolley only model: CT3405.Model CT3306 is fitted with 2 fixed & 2 swivel castors with non marking blue wheels & corner buffers. The unit comes complete with 6 containers.