i dont know much about the api of pureperms but i think u can assign permissions to a group why not just make a permission for the kit and give the said group that permission then just check if the sender has the permission for the kit
Code: $this->group = $this->getPlugin()->getServer()->getPluginManager()->getPlugin("PurePerms")->getUserDataMgr()->getGroup($sender)->getName(); //getting group of the player if ($this->group == (" group ")) { //check if they are in that group