Roller-type planimeter features unique 6-digit pulse count operation that permits cumulative measurement of areas up to 10m – 100 times the measuring capacity of ordinary planimeters. Includes hold and measuring control, clear liquid crystal digital readout, and scale readings in Metric or English. Enhanced with advanced micro-processors for accuracy. Easy roller operation – simply follow the outline of the area to be measured, the reading on the digital display corresponds to the area. Ideal for many applications where precise, large-area measurements are needed. Maximum measuring range: 325mm vertical; 30m horizontal. Accuracy: within ±0.2% (within ±2/1000 pulses). Packaged in a plastic carrying case with AC adapter (battery included) and operating instructions. Please note: No. KP90N has a computing function that gives the measurement readout in the scale desired (sq.ft., acres, etc.).