Go for the
LB1 High Performance New Super Cooling Fan It was designed specifically for the MSI GT70 Dominator Pro 890 i7 17.3 4900MQ laptop with the right size as well as the fans being ideally placed to ensure they are in line with the laptop's ventilation slots- this provides maximum cooling.
See: http
/www.amazon.com/gp/product/B00JQNKK8O/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00JQNKK8O&linkCode=as2&tag=newtomshardware-20