What is this?

I am confused, I got a cool new A3 printer (epson photo 1290) for christmas, which is great. It came with this weird bit of translucent plastic that like, splits in twoat one end. It doesn’t seem to have a use, isn’t mentioned in the manual as far as I can see, although it is shown but not named on the “what you should have in this box” section.

What is it?