This interlock kit fits Midwest panels having three branch breakers mounted to the left of a single vertical throw main breaker as shown. The distance from the main breaker cover cutout edge to the closest breaker cutout edge is approx. 2 3/16".
 
PLEASE NOTE THAT THE 2-POLE GEN BREAKER MUST BE MOUNTED IN THE TWO FAR LEFT BREAKER POSITIONS TO CONTACT BOTH BUS BARS. THE FAR RIGHT (THIRD POSITION) IS  COVERED BY THE INTERLOCK AND IS NOT USABLE.
 
This is not yet a full production kit so it is not blue anodized but is CNC machined with radiused corners and chamfered edges and looks professional and performs very well.