Manual windshield washer pumps were the norm in the 60's. The pump works on a simple internal diaphragm to create pressure for squirting the water. When connected with the correct diameter (small) hose it provides more than sufficent volume and pressure to allow for cleaning. With a small windshield this might not seem important until you consider the need to wipe off the mud or grime as you are still driving. The pump is typically mounted under the egde of the dash. These are new old stock as new production has long since stopped.