A system includes a processor and an external fuel indicator. The device also includes a touch screen input mechanism arranged on the front face and a plurality of tactile guides on the back face. The device is configured to alter its behavior when core saturation is detected such as by entering an MRI mode that may include cessation of therapy, fixed-rate bradycardia pacing, andor disablement of tachyarrhythmia therapy. The mask forms a skin onto which paint, varnish, or other coating material may have adhered or contacted and which resides upon a lubricated layer such that it may be slid, wiped, rinsed or peeled away.