Hello. Welcome to Futurlec. The electronic components Superstore. To find the component your looking for, either search by Part Number or visit the relative department. Need Help. TO-3 TO3BAL - TO-3 Compact Heatsink Photograph Features Suits TO-3 Devices Heavy Duty Aluminium Compact Siz Dimensions: Length - 45mm, Width - 15mm, Height - 38mm