Park Tool - OBW-2&3 Offset Brake Wrenches
PARK TOOL - OBW-2&3 OFFSET BRAKE WRENCHES
We call them an offset wrench because of the unique design, which allows it to be used in tight places, such as centring calliper brakes.
OBW-2 has 11mm and 12mm openings.
OBW-3 has a 14mm opening, while the other end fits into the tension springs to rotate the brake on its bolt.