An "A" style elbow refers to an elbow that, when attached to a downspout, angles the downspout frontwards
and backwards. A
typical Downspout installation would require the use of three elbows.
Two elbows are usually needed at the top of the downspout a backward facing elbow would attach to the outlet of the gutter and a frontward facing elbow would attach at the wall to span the
length of the eave so the downspout can be directly mounted to the wall
of the structure. One forward facing elbow is commonly used at the bottom of the
downspout at ground level to direct drainage away from the building.