The Primal Gear Take Down arrows are 31 inch long Victory VForce .245 Sport, 400 spine. Our patent pending take down system makes breaking arrows down for transport a snap. Just unscrew the arrow into two halves for transport, and screw the two halves together and you are ready to fire. These arrows have only been tested with the Compact Folding Survival Bow at arrow speeds up to 180 feet per second. It is best to wax the threads on the adapter with string wax to avoid loosening due to vibrations.