300Pcs 29mmx42mmx0.12mm Mica Insulator Sheet for TO-3 Transistor Product Name : Mini Mica Insulator;Material : Mica, Paper, Silicone Resin Package : TO-3;Size : 29 x 42 x 0.12mm/ 1.1" x 1.7" x 0.005"(L*W) Color : As Picture Shown;Hole Diameter : 4mm/ 0.16"2mm/ 0.08" Net Weight : 84g Package Content : 300(2%) x Mini Mica Insulator