3 Wheel Body Mass Index Calculator. Imperial and Metric measurements. Screen-printed in 1 spot colour directly on to the .020 White Vinyl Plastic material. This makes for a top quality, long lasting wheel. Use our standard template or supply your own customized one. Ideal for Family Doctors, Pediatricians, Fitness, Health, Nutrition, Diet & Insurance Industries among others. Custom imprint, Pantone colour match and bleed edge all included. Outside wheels 3.5" dia. & Middle wheel - 4.25" dia.