5 H0e flats based on the chassis of the Spoorijzer KW13 1m3 skips. It has Roco / Minitrains / Egger-Bahn compatible couplings.
The model is designed to been used with these axles. But any H0e axle ~14mm wide and with a flange no larger than 7.6mm in diameter will do. Some examples are the Sehling RDS4.3-SH0e wheels, Metal Wheels from Nigel Lawton or Roco / Fleischmann 20024.
How to bend the coupling is described in this forum post.