KLIM Tempest Laptop Cooler with Vacuum Fan - New - Gaming Laptop Fan with Display - Temperature Detection + Automatic/Manual Mode - 4000 RPM - Portable - Compatible with Laptop Cooling Pads

Neither. Unlike Windows laptops, Mac’s do not have open bottoms. You’ll only be cooling the chassis, and since you most likely wouldn’t have a thermal pad in between the SoC and chassis, it would be greatly inefficient. If anything, I’ll suggest you get a cooler/fan that directly blows into the out-vent (in the back) or in-vent (in both sides).