Pair of matched borosilicate glass 6" mirror blanks, ground and partially polished to rouge stage; f8. The pair includes the mirror and the tool containing pitch lattice and embedded rouge. The cell to which the mirror is fitted is aluminum, and includes three spring-biased angular adjustment collimating knobs for precise axial alignment of focal point on diagonal. Mirror can be easily  finished through tin oxide and cerium oxide stages for silvering. 1/8 wave or better finish should be achievable.  1st photo shows the mirror blank and the tool; 2nd photo shows mirror in the cell. Photos 3 - 5 show the cell, front, side and back.