Red Pen for Hygrothermograph

So economical, you’ll want several for monitoring and recording environmental conditions This hygrothermograph is so compact it fits almost anywhere- measures just 6.125"L x 7.5"H x 4"D. Quartz-controlled drive is employed for accuracy; operates for six months on one AA battery. Includes two felt-tipped pens (blue and red), one 7-day rotation chart and one AA battery. Compact size fits almost anywhere Record temperature and humidity on 7-day rotation Protective acrylic cover removes easily yet latches securely in place