Life Blue Tube Air&trade; Radiation Free Headset Earbud 2.5mm Custom Molded - Lightweight Earpiece. RF3 Lightweight AirCom (tm) Sound Delivery Tube and Headset Size: 2.5mm or 3.5mm. State-of-the-art sound chamber with enhanced SPL technology. Tube Clip,Tangle-Free Expansion Cord,Optional lightweight titanium ear hook design. Fully adjustable and rotate 360 degrees to fit either left or right ear.