Check the listing for details. Generator Interlock Kit for Challenger, Westinghouse, Thomas & Betts. Condition: New. Listed at 62.77 USD. This Generator Breaker Interlock Kit fits Challenger, Westinghouse, and Thomas & Betts 200 Amp Panels with 1" to 1 1/8" vertical spacing between main and generator breakers (please see photos to insure proper fit.) GenSafety manufactures a very high quality line of generator breaker interlock kits. The interlocks are CNC machined from high grade aluminum and are then color anodized to prevent corrosion and insure smooth operation for years to come. These kits and Made in the USA and include everything needed to complete the installation including a high quality drill bit, name brand thread locking compound, all hardware, a breaker tie down strap, easy to follow instructions and a complete decal set. Once you install an interlock kit from GenSafety you won't want to use anything else! "We make you look good!"