Truth window part

Hello, i am trying to locate truth replacement part for my casement window, i dont know what brand window it is as i am the second homeowner, but the part is a truth part stamped on part, i beleive its called a plastic guide for the vertical metal rod , there is upper and lower guide , in the picture is the broken guide, if you can locate the part or direct me to somewhere i can find the part so i can repair the window , i could use like 6 of the part as i have a couple broken ones , thanks for your help