There are a variety of air hose quick couplers on the market

There are a variety of air hose quick couplers on the market. While the name suggests it's a quick coupling, they're actually a series of fittings that interconnect and seal pipes.
Couplers can be manual or automatic. The automatic ones plug into each other automatically and close when the male part is inserted, whereas the manual ones require you to pull the collar to insert and remove the air hose. You can tell the difference between the two by counting the stripes on the coupler. However, there are a variety of differences between the markings and types, so it's important to do some research before making a purchase.
Air hose quick couplers are useful for many applications, including plumbing and manufacturing. They make it easy to connect air hoses to pneumatic tools. These fittings usually have an internal o-ring, which seals when disconnected, eliminating the need for a shutoff valve. They also offer more flexibility in connection, which means less kinking in the hose.
One of the most common uses for these air hose connectors is when you want to connect air hoses to spray guns. Quick Couplers provide female and male threads, and can be threaded onto a standard 1/4" NPT air hose connection. They are great for many different applications and are a must-have for any air compressor.

R134 Straight Column Quick Coupling Connector

Specification:

Brand New and Good Quality

Model: R134A

Material: Zinc alloy

Color: blue/red

Length:50cm

Blue Inside diameter: 14 mm

Red Inside diameter: 17 mm