The Alpaca Cinch is used to help keep the bikes apart on the carrier (as shown in Photo 1).  The Alpaca Compact can be used with our patented clamp (as shown in Photos 2&3), or with our Trailer Mount (as shown in Photo 4 mounted to a hitch extension sold separately).  The Trailer Mount can also be mounted on a trailer.  The Clamp greatly reduces stress on the hitch while adding strength to the carrier as well as eliminating rattles.  The Alpaca Compact will carry most types of bikes including unique frame bikes (Photo 2) and most recumbent bikes (Photo 4).