The Convoy Solo Rack is designed to sit behind the rider's solo seat directly over the fender.
 
An optional helmet lock with tamper proof hardware can be mounted to either side.

Designed to offer versatile storage with strap, hook, and tie down points. Offered in a durable sand textured black powdercoat. Heavy duty .125" steel construction.

There is a slot and attachment point for mounting an adjustable backrest; available separately at the link below:
https://www.combustionindustries.com/product-page/convoy-backrest-pad-and-support