This is a dart holder for the Nerf Disruptor. It clamps around the front of the gun and you don't loose space on the top rail. It has a nice snugg fit and doesn't come loose while loading or unloading darts.
It can hold 24 darts, always one dart in front of another one.
I also recommend waltherion's dart holder (https://www.thingiverse.com/thing:714721) because it fits nearly every Nerf. Like shown in the picture, you can hold up to 40(!) darts if you also print this and my design (24+10+6 in the magazine).
Have fun printing and enjoy your fights :)
I recommend printing in the original orientation and unsing a bit of support for the bridging gap. Might also work without supports.
20 % Infill and 2 perimiters should make it strong enough. It took 4 hours to print and about 40 grams of PLA filament.