looking for the front piece that adjusts the spray?

a piece thats on the end that adjusts the spray has broken off do you know where can i buy one of these. it is a pressure washer. champion cpw 1600 there is a number 256270501781 and on the piece that its on is 2620650 just near that number is pa66gf30.also there is on the machine 89dB. i have no manual with any addresses or telephone no.i would be more than happy if somebody can help .thanks. taffy.