A crop harvesting header for a harvester comprising: a main frame structure extending across between two ends of the header across a width of the header for movement in a direction generally at right angles to the width across ground including a crop to be harvested; a mounting assembly for carrying the main frame structure on the harvester; a cutter bar across a front of the main frame structure carrying a cutter knife operable for cutting the crop as the header is moved forwardly across the ground; a crop transport system (12, 13, 14) for moving the cut crop toward a discharge location of the header for feeding the crop into a feed opening of the harvester; first and second crop dividers each at a respective end of the main frame structure and defining an end wall confining cut crop onto the transport system (12, 13, 14); and first and second cutting devices each mounted on a forward end of a respective one of the first and second crop dividers for cutting and dividing crop at the respective divider; each divider having a hydraulic motor and an output coupling mounted on the divider for providing drive to the cutting devices; each divider having a mounting assembly thereon for coupling to a cooperating mounting assembly on the cutting device by which the cutting device is attached to the crop divider for operation and released from the crop divider when not required; each cutting device having an input coupling thereon for cooperating attachment to the output coupling arranged such that the input coupling and output coupling are released from cooperating attachment by the release of the cutting device from the crop divider; and characterized by the mounting assembly of the crop divider including at least one bar member located at one of the top or bottom of the crop divider for hooked engagement with a cooperating component of the cutting device and a latch at the other of the top or bottom of the crop divider for pulling the cutting device into engagement with the crop divider, and wherein the cooperating input and output couplings (42, 41) are located between the top and bottom of the crop divider. a main frame structure extending across between two ends of the header across a width of the header for movement in a direction generally at right angles to the width across ground including a crop to be harvested; a mounting assembly for carrying the main frame structure on the harvester; a cutter bar across a front of the main frame structure carrying a cutter knife operable for cutting the crop as the header is moved forwardly across the ground; a crop transport system (12, 13, 14) for moving the cut crop toward a discharge location of the header for feeding the crop into a feed opening of the harvester; first and second crop dividers each at a respective end of the main frame structure and defining an end wall confining cut crop onto the transport system (12, 13, 14); and first and second cutting devices each mounted on a forward end of a respective one of the first and second crop dividers for cutting and dividing crop at the respective divider; each divider having a hydraulic motor and an output coupling mounted on the divider for providing drive to the cutting devices; each divider having a mounting assembly thereon for coupling to a cooperating mounting assembly on the cutting device by which the cutting device is attached to the crop divider for operation and released from the crop divider when not required; each cutting device having an input coupling thereon for cooperating attachment to the output coupling arranged such that the input coupling and output coupling are released from cooperating attachment by the release of the cutting device from the crop divider; and characterized by the mounting assembly of the crop divider including at least one bar member located at one of the top or bottom of the crop divider for hooked engagement with a cooperating component of the cutting device and a latch at the other of the top or bottom of the crop divider for pulling the cutting device into engagement with the crop divider, and wherein the cooperating input and output couplings (42, 41) are located between the top and bottom of the crop divider.