The Push - In One Touch Fittings series pneumatic piping joints excelling in quick fitting, accurate jointing and compact design are suited to the pneumatic systems necessary for automation and labor saving. The tube can be fitted and detached easily, so that workability is remarkably improved. Pressure loss is reduced. A large volume of compressed air can be fed with least pressure loss without air leak. Moreover the joints have a compact design. Thus the joints will satisfy strict user's demands.