I was very hesitant to get this because people said the Rebel Mech's 30 dart drum magazine was compatible with other stuff when it's actually a tight fit in my Nerf blasters, difficult to get out, and may go too far up so you have to manually push it down so the pusher doesn't ram darts into the upper part of the breach. I DO NOT personally recommend anyone get the Rebel Mech just for it's drum.
This thing on the other hand is great! Was able to load it up without any trouble. It comes with the shown Blue/Yellow darts x30. If you are curious, no, it does not have the little knob on the back or front that some drums have to assist with loading. It is very close, visually to the dimensions of the errant drum mentioned before, but it worked perfectly on the blasters I tested it on and had none of the issues of the bad drum. Quickly releases and isn't too tight in the magwell. Doesn't feed too far up into the blaster. Easy peasy to load. As mentioned in the details, it does work on the Nexus (and Aeon) also tested it with a Stryfe, Rapidstrike, Demolisher, Longstrike, and a knockoff Chinese Rayven. All unmodded.
If you want a 30 dart drum that's pretty compatible across the board and Nerf is too expensive or simply not available, THIS is your drum. It is available through Blasterparts for a little cheaper, but that's a German company and idk what it would do to shipping if you live in the states.