This part is very similar to part "Brompton Superlight Front Wheel Axle & Fixings." The differences in these two items are aesthetic and either axle will work with Brompton Superlights (the predecessor to the P Line), P Lines, and Bromptons with Dynamo wheels.

Note that this axle does not work for standard Brompton wheels without a Dynamo nor the T Line, as that bike requires its own axle.