Arm measures 9-1/2" loop to loop in the shortest position, and 14" when it is the fully extended . The loop on the left side is 3/8" diameter. The hole spacing on the right hand side of the picture shoe is 1-3/4".
This is the New Style Hold Open Arm from International Door Closer. In July of 2014, the old style was discontinued. Look under "More Views" to see the Old Style. Shown in Dark Bronze, ships with all components in the picture.
International Door Closer 3010-JO Arm and Track for Offset Top Arm Assembly Mortised Type (9/16" Depth of Top Rail). Track measures 15-1/4" long by 3/4" high by 15/16" wide.
International Door Closer 3020-VO Arm and Track for Offset Top Arm Assembly Mortised Type (7/8" Depth of Top Rail). Track measures 12-5/8" long by 1/2" high by 1-1/4" wide.
The International Door Closer 3010-S Side Load Arm is used with the 200, 300 and 500 Series Concealed Overhead Door Closer for Center Hung Doors. The arm is constructed of cast iron and measures 10" long, and 7/16" thick. The package includes all the mounting screws.