We manufacture the one and only ECG Pen Caliper, Penguin Pocket Caliper, Stent Caliper. Our calipers were invented by well known cardiologist, Robert A. Mackin, 20 years ago. His idea was developed after using the old style calipers, he noticed they were heavy in weight, they could not be carried in your pocket, they were very easy to loose and he had to replace them frequently.Today we have the Pocket Penguin Caliper. This caliper is designed to be clipped in your pocket with a brass powder coat cap that is not only useful to prevent accidental punctures by the caliper tips, the cap also gives a great sophisticated look. On this cap we have the capability to engrave your name, the logo of your company or lately for educational purposes we are engraving the interval scale. The scale is practical in the daily use for cardiologist, physicians and nurses. Mackin Manufacturing has developed an area exclusively to create and invent new varieties of calipers and other pocket tools. We have now more than 20 products and they are growing now in to other industries. Visit our website www.mackinmfg.com we have most of our products displayed.We manufacture so we mainly do wholesale but for all those who know the quality of a Mackin product and do not know where to get them, we supply your needs.Specialties: new ventures,expertise requests, business deals, reference requests, getting back in touch.