CAMP Steel Linking Bars

CampSaver.com says:
C.A.M.P. XLS/XLS Nanotech Aluminum Linking Bars Pair. 5 cm rigid aluminum linking bars. See specifications for compatibility. Sold in pairs. Specifications for C.A.M.P. XLS/XLS Nanotech Aluminum Linking Bars: Manufacturer: C.A.M.P. Length: 17.5 cm Fabric/Material: Aluminium Additional Features: for XLC 390 / 470 / 490 XLC Nanotech Quantity: Pair Features of C.A.M.P. XLS/XLS Nanotech Aluminum Linking Bars: 17.5 cm 15 holes XLC 390 / 470 / 490 XLC Nanotech Package Contents: C.A.M.P. Xlc/Xlc Nanotech Aluminum Linking Bars (Pair) C.A.M.P. 95: XLS/XLS Nanotech Aluminum Linking Bars Pair