So, back to the original question about what MOD means. Well MOD is the ratio of the pitch circle diameter (PCD) to the number of teeth. DP for imperial gears is the number of teeth per one inch of pitch circle diameter. So whilst that may well answer the question, it doesn't really help appreciate the size of a gear.
doer. n. 1. a person or thing that does something or acts in a specified manner: a doer of good. 2. an active or energetic person. 3. a thriving animal, esp a horse. (Ëdu Ér). n.
A. The blessed hearer and doer looks intently at the word. Rather than a quick glance, the doer of the word looks intently at it. The Greek word means to stoop and look carefully at something. It was used of John and Mary stooping to look carefully into the empty tomb after the resurrection (John 20:5, 11).