Just checking Hobby People's website for retracts and although guys here have been saying the P-47 comes with Magnum .40 size retracts Hobby People lists two different part numbers and prices for the Magnum retracts and Modeltech P-47 retracts. The Modeltechs cost 50% more:

237940 Magnum Retract Gear, Mech. 40 Size Mains 19.99

120203 Modeltech Retract Set - P-47 ARF 60 30.00

FWIW..............