Mosmatic T304 SS 3/8" Female QD Coupler

SKU: MM-70.017
Mosmatic T304 SS 3/8" Female QD Coupler
Mosmatic T304 SS 3/8" Female QD Coupler
Mosmatic T304 SS 3/8" Female QD Coupler
Mosmatic T304 SS 3/8" Female QD Coupler

Mosmatic T304 SS 3/8" Female QD Coupler

SKU: MM-70.017
Regular price $59.85

I worked closely with Jaimie from Mosmatic US to have these high-end quick disconnects made for us, the discerning prosumer. The Mosmatic T304 SS 3/8" Female QD Coupler would be used on a High-Pressure Hose or any other 3/8" fitting that's NPT threaded.

I wanted these T304 stainless fittings at any cost, and my guess is that many of you do too. I get that this is more expensive than brass or Chinese-made stainless, but the fit, finish, and precision makes it worth it. These fittings are special because they're manufactured in Switzerland with much greater precision than typical fittings.

All of my new Mosmatic fittings come with a 6-month warranty, but I suspect they'll last for quite a while. These couplers have a satisfying action to them, and even the sound they make sounds stout.

Do keep in mind that these are a consumable. These are like tires that will be susceptible to wear and tear and future replacement. They are just much better than normal.


- Brand: Mosmatic

- Material: T304 Stainless Steel

- Inlet: ⅜" Female NPT

- Outlet: ⅜" QD Coupler

- Warranty: 6 months, for manufacturing defects (does not include o-rings).

FAQ & Support

Why is my 3/8" coupler leaking from the end?

Pressure Washer Fittings 101: Fittings and QD Naming

Pressure Washer Fittings 102: Applications and Usage

Pressure Washer Fittings 103: Spray Nozzles


To install your female 3/8" couplers on the ends of your High-Pressure hose (or other 3/8" NPT terminated hose) you will need the following: 

1. Teflon tape (it is not recommended to use thread sealant)
2. 11/16" and 22mm for the hose. And a 24mm for Mosmatic couplers, or 1" for MTM couplers. DO NOT use pliers or adjustable wrenches. You will NOT be able to get the connection tight enough. 
3. Workbench with a vise is preferred, but not necessary.

To install: 

1. Put 7 wraps of Teflon tape on the male ends of the hose. 
2. Use the 11/16" wrench on the smaller end of the hose, and brace on the ground or clamp in a bench vise. 
3. Use the 24mm (or 1") wrench to install the coupler by pushing against the other wrench. You will need to really put your weight into it and get it TIGHT to prevent leaking. 
4. Repeat this process on the other end of the hose with the 22mm wrench on the swiveling hose end. 
5. Connect to pressure washer and gun, check for leaks.

x1 Mosmatic T304 SS 3/8" Female QD Coupler

This item is shipped from our warehouse at OGHQ in Lady Lake, FL. Shipping costs calculated at checkout.

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