Product review (4 stars): L shape brackets main hardware to support this range hood
I needed 4 L shape brackets; 2 on the back ( supplied, thanks) and 2 on the front that need to be screwed onto the sides of the cabinet i.e. inside the cabinet on the left and right; the flat brackets are supported onto a weak part of the cabinet; this way the brackets are out of the way as well; these 4 L brackets should measure 2" on the round hole side and 3" on the slotted hole side.  Found an L shape bracket (see foto) but it is a thinner metal and I am not sure it would support 1/4 lbs of the total weight.
On step 6, secure hood to back wall, seems not need it since manufacturer did not provide holes.  Is it possible that you can send me these additional brackets with a heavy thickness and with the above measurements