Features:

Optical Properties

Bulk Absorption Coefficient When 10.6μm <= 0.24 cm-1 
Temperature Change of Refractive Index When 10.6μm 41 x 10-6/°C 
Refractive Index Inhomogeneity When 10.6μm < 100 x 10-6 

Thermal Properties

Thermal Conductivity when 20° C 0.167 W/cm/°C 
Specific Heat 0.469 J/g/°C 
Linear Expansion Coefficient When 20° C 6.8 x10-6/°C 

Mechanical Properties

Young's Modulus 74.5 GPa (10.8 x 106 psi) 
Rupture Modulus 103.4 MPa (15,000 psi) 
Knoop Hardness 210-240 kg/mm2 
Density 4.08 g/cm3 
Poisson's Ratio 0.27

Specifications:

for example
Diameter, mm Thickness, mm
10 * 2
12.7 * 2
12.7 * 3
19.05 * 3
19.05 * 4
20 * 2
20 * 3
20 * 4
25.4 * 3
25.4 * 4
25.4 * 5
38.1 * 4
38.1 * 6
38.1 * 9
50.8 * 6
50.8 * 8
50.8 * 10

Applications:

Windows, domes and lenses for therma-imaging system