It is for general purpose coupling for connecting air supply to pneumatic tools. Critical parts heat-treated for increased strength giving greater durability and resistance to wear. One-way automatic shut-off valve in socket.

Y series is one-touch coupler with big body.
Available models: YHN, YHH, YHM, YHF

20 30, 40 series is two-touch couplers.
Available models: 20SP, 30SP, 40SP, 20SH, 30SH, 40SH, 20SM, 30SM, 40SM, 20SF, 30SF, 40SF

20PP, 30PP, 40PP, 20PH, 30PH, 40PH, 20PM, 30PM, 40PM, 20PF, 30PF, 40PF are matched with Y series one-touch and 20 30 40 series two-touch couplers.