31-P873N-401 >>> One Piece CPU/VGA heatsink for GTX 1070/1080 (desktop) 200W MXM 3.0 in the P870DM3s.
If you are upgrading your P870DM3/P870DM3-G to the GTX 1070/1080 desktop GPU, this is the heatsink required
Link to the Nvidia GTX 1080 Desktop Video card for the P870***sale.