I. Neotherm Aulektro cobalt blue glass II. Used for furnace or klin viewing III. Size: 3 ¼” x 4 ½”, 32mm diameter, 53mm diameter, 37mm diameter, etc. IV. Size available as per client requirement. V. Made in Germany. VI. Type: -12 DIN -14 DIN VII. Colour: -Green (B) -Blue (BL) -White