Workspace Units: MM

Step 1) Create a new sketch on the front plan and create the following sketch. All share centered at the origin:

(Click image to enlarge)

Step 2) Extrude 1:

Step 3) If sketch 1 is hidden, make sure to show it

Step 4) Extrude 2:

Step 5)Fillet :

Step 6) Add a chamfer:

Result