The optical layout include 8 aspheric mirrors. The biggest one correspond to the first collimator with a size of 25cmx25cm. The weight of the rought mirror is 13kg and the mirror holders require special mechanical considerations. In addition, mirrors has been lightened decreasing their mass. Both mirrors and brackets are made with same material as the bench (Aluminium) in order to have same contraction at cryogenig temperatures. Brackets and blank mirrors were manufactured in our machine shop and are ready to be mounted on the bench as soon it is done.