Had the Accutire MS-4021B checked at our calibration lab on a NIST certified master gauge -.02 Psi that's pretty good if (typeof amznJQ != "undefined") { amznJQ.onReady('jQuery', function() { amznJQ.available('popover', function() { var widgetDom = jQuery("#R3O09TLRR73E17_imageSection_AFCA0694-DC0C-11E7-AE15-74C14C00B2E6"); var images = widgetDom.find(".review-image-thumbnail"); for (var c=0;c