The Simpson Strong-Tie A34 Framing Angle is made of galvanized steel and measures 1-7/16" x 2-1/2". It is designed for use in construction projects to provide structural support and reinforcement. With a rail height of 1 1/2 inches and a length of 12 inches, this framing angle is commonly used to join wood pieces together securely. The set includes 7 framing angles, making it convenient for larger projects requiring multiple connections.
The pros of A-34 brackets are so many it would take a whole page to list. The main plus is that you can use them when you can't toe nail or screw. The other big plus is when used right it makes your connection incredibly strong .
The only con that I can think of is that sometimes you have to drill out the holes for a bigger fastener.