We will exchange your existing SONY CD 900 ST with a foldable headband (MDR 7506). This makes it very convenient to carry. Please send us your headphones. (You are responsible for the shipping both ways).
Any arm band of the SONY Z700 etc can be exchanged for one of our Ultrasone parts which is highly durable, less prone to cracking and has a greater movable range than the standard arm. (You are responsible for the shipping both ways).