Looks like the ante has been upped for these. Some deals around direct through Senn and also Amazon but this puts the best current deal at JB with the free USB adapter.
4 Colour choices all at the same price ($419 before Perks code).
Bonus Offer - Get a Bonus Sennheiser BTD 600 Bluetooth USB Adapter!
Purchase this selected Sennheiser Momemtum 4 headphones and get a bonus Sennheiser BTD 600 Bluetooth USB Adapter when you add to cart.
Groovy ear muffs