Abstract: A distribution assembly for product delivers and deposits a precise quantity of product on a support. The assembly includes a cylinder, a piston, displaced in the cylinder by an actuator, a route for taking in the product, an ejection head with a slide valve movable between a first closed position and a second open position, and an outlet nozzle, a preparation chamber, a transfer passage, connecting, selectively the preparation chamber with the outlet nozzle. When the cylinder comes towards the support, the physical contact with the support moves the slide valve from the first position to the second position and triggers delivery of the product, pushed by the piston, via the transfer passage. When the piston arrives at the forward end of range, the piston moves the slide valve from the second to the first position, closing the passage for the product via the transfer passage.