This is a Package of Twelve 36" HO Scale Flat Back Wheel Sets by Bachmann. Suitable for Ages 14 & Up. FEATURES: Replacement wheel sets with needle-point bearings NMRA RP25 wheel contours Carded packaging INCLUDES: Twelve 36" HO scale flat back wheel sets REQUIRES: HO Scale Train Equipment Adult Supervision SPECS: Scale: HO 1/87 COMMENTS: Keep small parts away from children under 3 years of age. tlw 10/21/08