Square D 1-in Generator Interlock Kit in the Breaker Box Parts department at Lowes.com
Generator Interlock Kit legal in SC ? : r/AskElectricians
Amazon.com: Natupal Generator Interlock Kit Compatible with Square D QO or Homeline 150 or 200 amp panels. 1 3/8 inches Spacing between main and generator breaker, Professional and Interlock Kit : Tools & Home Improvement
GenInterlock SD-200A Square D Electrical Panels Interlock Kit for Safe Outdoor Portable Power Use During Outage, 150 and 200 Amp: Amazon.com: Industrial & Scientific
Interlock Kit K-8610 | Interlock Kit
Interlock Kit K-1512 | Interlock Kit
Square D Homeline 150 - 225 Amp Outdoor Load Center Generator Interlock Kit HOMRBGK2C - The Home Depot