Quantitative product includes a compressed air source, a compressed air pipe, a pair of compressed air piping, a glue gun and a timing controller. Are arranged in the main compressed air pipe pressure regulator, pressure gauges and a three-way valve and one end connected to the compressed air source, the other end of the hose connection. Under compressed air connected to the compressed air source and piping are arranged adjustable valve and pipe connector and connected with the atmosphere, and thus is a negative pressure differences inside pressure. Piston-type glue gun with air pressure-driven and precise control of timing controller makes glue out from the needle, and negative pressure suction effect on viscose, glue guns there will be no residual droplets.