This interlock kit fits Square D panels with a single vertical-throw main breaker and 3 1/4" to 4" from main breaker to branch breaker as shown.
 
These kits are made in USA and are VERY high quality. The kit includes everything necessary to complete the installation including a correct size high quality drill bit, name brand thread locking compound, a complete decal set and very clear installation instructions. The interlocks are precision CNC machined and then are color anodized for extreme corrosion resistance and lifetime smooth operation.
 
Once you install an interlock kit from GenSafety you won't want to use anything else!
 
We stock all of our kits and they normally ship same day.