The Hopkins Vehicle To Trailer Plug In Adapter- 47355 - 7 Blade To 4 Flat Wire is a black adapter designed for direct replacement in trailers. manufactured by Hopkins Towing Solution in Mexico, this product is a 7-blade to 4-flat wire adapter that provides a secure connection for towing purposes. It is important to note that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, please refer to the manufacturer's installation sheet and warning labels.