Your earpiece there should have a small plastic adapter that pushes in and twists to lock the tube in place. If the adapter included with our tube does not fit your earpiece, you can remove the adapter from our tube, and use the adapter for your existing earpiece with our tube. If the fit is loose at the base of the tube, you may need to trim off a small piece of tubing for a tighter fit. If you still are having issues, send us a picture and we'll help you work through it.