1. Aluminium Heatsink for TO-247 power semiconductor packages 2.TO-247 Heatsink Size: 1.5"x1.34"x0.47" / 38x34x12mm 3. Weight: 0.53 oz / 15 gr 4. Can be applied for cooling voltage regulators LM78XX, LM317, TDAXX etc 5. Hole threaded size: M3, thickness: 1.5mm