Roto Molded Rack Expansion Case (with wheels)Product Overview The 1SKB R1906 was designed to add expandability to the 1SKB R102, 1SKB R104, and 1SKB R106. The 1SKB R1906 can even stack on itself (remove the casters from the top one before stacking). This case comes with Travel Sentry Approved locking latches installed. Using Travel Sentry Approved locks allows your luggage to be opened, inspected, and relocked by TSA authorities without damage. For more information, visit www. travelsentry. org.