6 Pieces (100mmx25mmx10mm/ 4" x 1" x 0.4") aluminum cooler heat sink. This heat sink can be used for passive heat dissipation of various DC converter circuit boards, , Power IC and Transistors, etc 6 Pieces Aluminum Heat Sink Size: 4" x 1" x 0.4"/100mm*25mm*10mm (L*W*H) Unit weight : 33g Can be used for cooling , Power IC and Transistors, etc