These are various 22 mm quick connect by Screwing together Pressure Washer adaptors.
They are used to join your standard M22 Karcher type pressure washer connections,
to either a 1/4" or 3/8" wash hose depending
if it has a Male or Female BSP Hose end connection.

On The Female M22 Karcher, the internal thread is a 22mm metric thread and
the internal spigot with the O ring measures 13.9mm OD (14mm)
Also available 22mm to Female 3/8 BSP and 22mm Male to 1/4 Male.

The M22 Style "Karcher" Connection has been almost globally adopted as an
Industry Standard on most Domestic and Some Commercial Pressure Washer Applications.