Notes: "This is the larger version of Stanley's adjustable (""sliding bar"") polar planimeter, model A8031 in early catalogs and Q59 in later catalogs. On the standard size planimeter the pole and tracing arms are approximately 8"" and 9"" long. On this planimeter they are 11"" and 16"" long respectively. Because of the larger areas that will be measured, the multiplier wheel is geared down and counts up to 25 revolutions of the tracing wheel, vs. 10 on the standard size model. Both a checking rule and magnifier (to read the vernier) are included."