Exwell via Amazon offers the Exwell Digital Tire Pressure Gauge for $29.99. Coupon code "6QOBDDLT" cuts it to $20.99. With free shipping, that's around half of what most third-party sellers charge, although we saw it for a buck less a week ago. It gives readings from 5 to 150PSI and features a digital backlit display and plug-type nozzle. Deal ends October 31.