Abstract: The disclosure relates to a pressure sensitive indicating device of extremely simplified nature, providing a visual indication of a predetermined pressure threshold level. A typical and advantageous form of the device is a valve or valve extension member for a pneumatic tire, providing a visual indication of the existence or not of a desired pressure level. The device, in its most basic form, comprises an element formed of a natural or synthetic deformable elastomer, designed to expand upon exposure to increasing pressure levels. A covering element is associated with the deformable elastomer and is displaced by distention of the elastomer. By providing the deformable elastomer in a distinctively different color than the cover element, the displacement of the cover upon pressurization to a desired threshold, is readily evident to the observer.