Hard Metric, Standard Backplane Connectors conform to a set of specifications for interconnection devices. These devices are used in board or panel systems where other circuit boards can be plugged into. These connectors usually have a 2.0 mm pitch from row to row and column to column. The number of positions range from 3 (Power) to 308 (220 + 88 Ground) in Pitch dimensions 0.050” (1.27 mm), 0.071” (1.80 mm), 0.079” (2.00 mm), 0.150” (3.81 mm), or 0.295” (7.50 mm).