Specifics about this wheel set:
Insulated Axle: The 2 wheels are insulated from each other; for 2 rail DC
Wheel Diameter “D” = 0.475 inches (12 mm)
Axle Length “L” = 0.976 inches (24.8 mm)
Design: stepped end axle (Nadelachsen or Needle Axle)
If your car uses 3 rail AC wheel sets (70002), you can replace them with these Marklin (70053) / (700530) - 2 rail DC wheel sets and the car will now work on a 2 rail DC layout.
This (70053) / (700530) (DC) wheel set [or 70002 (AC)] fits the following Cars: Primex 4556, 4611, 4617, 4618, 4671, 4912, 4917, Crane Cars, Depressed Center Flat Cars 4617 & 4618 with 3 Axles; Tender of locos 3003, 3046, 3086, 3089, & 3094