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
Generator interlock kit for Square D QO 150 & 200 Amp WR 22 SqD QO | eBay
Panel Interlock Kit Kits - for safely connecting generator power without a transfer switch