Build your own customizable blaster with the mini cross fires up to 75 feet set includes knex rods and connectors plus special parts to create your blaster 1 blaster chamber 1 quick fit grip 1 preload ring and 5 foam darts combine with the k 10x for an awesome downloadable combo build compatible with the entire k force build and blast line ages 8r featuresr 5 foam dartsr 1 blaster chamberr 1 quick fit gripr 1 preload ringr downloadable combo build