This Kit is meant to go with my upgrade set for JB Bruticus which can be found on my models page. When that kit is installed on the combiner we are left with the trailer which previously transformed into Bruticus's thighs and lower waist and crotch. However with the upgrade kit the trailer is no longer required. I designed these to weapon sets to give the trailer a new purpose and give owners options to either have a really big sword or a really big gun.