Best used as a replacement rudder part for classic Wilderness Systems and NorthWest kayaks, such as the Seascape, circa 1990s. Block is 4 5/8 inches long, 2 1/8 inch wide and 1/2 inch thick. Five holes are machined into the block; one for the pin (pintle) that fastens to the bracket in an up and down orientation, one for the rudder blade to rotate on (side to side orientation), and three more side to side that screws pass through (top screw to bottom screw holes are 1 5/16 inches on center). The original block could be white or black. OS Insert RBAP