This is another version of a wall mount for the Amazon Echo Dot printed using the following settings:

Layer height: 0.2mm Perimeters: 3 Top and Bottom layers: 4 Infill: Rectilinear 50% (could be 100%) Print with PLA at 205C nozzle and 60C bed.

You need to print the three brackets on their edge to ensure the grain is right for strength; the base needs to be printed with the slots uppermost. You may need a little gentle filing to fit the brackets and they will need to be superglued into position, then clean up the countersinks to ensure the fixing screws sit flush.