Rybro's Castors and Wheels

The Rybro Castors website suggested that rubber wheels instead of nylon wheels would be better on my wooden office floor which has 2mm gaps in between the slats. I ordered castor wheels for my office chair, on Monday 1st Feb and Courier Guy delivered them 48 hours later, on the morning of the 3rd Feb. My chair glides across my floor and I am delighted with Rybro's online service and efficiency using the courier Guy. Thank you!