Insulation Sheets For Package TO-3 Transistor.
Material: Silicone/Mica/Alumina (Aluminium Oxide)
Size : A 42mm, B 29mm.

Thickness: Alumina - 0.8mm (Thermal conductivity (30 W/mK))

Silicone/Mica - 0.2mm 

Insulation Sheets For Package TO-220 Transistor.
Material: Silicone/Mica/Alumina (Aluminium Oxide)
Size : 19mm, 13mm.

Thickness: Alumina - 0.8mm (Thermal conductivity (30 W/mK))

Silicone/Mica: 0.2mm

HS: 8546200000