yep shershah - there are only a couple of shops there that deal in them, be sure to buy a brass body Karcher or Kranzle unit - I had a Kranzle 2000 psi item, its repair seals are available in Karachi at Bombaywala very easily. Test the motor for correct operation.
btw it does not mix air with water its just a hydraulic pump that pressurises water with little volume to 2000 psi and it jets out of a tiny orifice, thats how you get the blade type cleaning properties of it.
Be very very very careful when using it, if you spray it direct on your skin - you will have no skin, if you spray realy hard and upclose to your cars paint it will rip the paint. Practice first. use the plume (ball of water) to wash the finish, and jet to wash off mud from hard parts like the undercarriage.
my kid brother enthusiastically washed the front gate of the house and it was missing quite some paint afterwards, I had to repaint it. But its a nice item, clean car, clean motorcycle, clean house (Mrs, Mom, Sis etc. love it) that way you dont need to hear their complaints.
my stupid neighbors used to pull up their cars saying "hamari gaari ko bhi service kardo please"