Knitting machines kx350 brother

I got this machine from a friend. I have been googling and keep coming up with something about a sponge to hold the needles in place. I don’t see a sponge on this machine. Does anyone have this model and know anything about a spounge?
THank you.

The sponge is about a half inch wide, and maybe about 3/8’s of an inch thick and as long as the needle bed. It is located at the very front edge of the needle bed, under the edge. You can only see it by looking at the sides of the bed. I take a chop stick and push mine out when I change needles or the bar itself. If the sponge bar is worn out or too old you won’t be able to knit with the machine till the bar is replaced. You can push the bar out a little ways go to the other end of the machine where it comes out and look at the sponge if it is indented really bad or feels or looks dry it needs to be replaced.