Aeron alternative armrests

I like my type C classic Aeron, but the big issue is that the armrests are to long, which forces me to sit to far back from my desk. I'm unable to move them for or backwards. Besides that the shape is also annoying, as the humb pokes in my arm.

Does anyone know if there alternative armrests? I Googled, but could not find much. I'm based in the EU, so there is also les available.