HS-PI-C 3Pcs Aluminum + Copper Heatsink
This is a great product for passively cooling your RPI 3, this pack comes with two aluminum heatsinks for the CPU and 4x USB with Ethernet Controller IC. The copper plate is recommend on the backside for the ram. Each heatsink comes with thermal tape for easy mounting.
Dimensions:
Green Heatsink: 14 x 14 x 9 mm (LxWxH)
Copper Heatsink: 5x9x9 mm (LxWxH)
Black Heatsink: 12x12x1 mm (LxWxH)