Erasers can be a pain because they get filled with graphite and smear your drawing, they run out in no time, and sometimes they’re just too hard to do any good. A kneaded eraser will solve all those problems. It picks up graphite MUCH better than any regular eraser, and when it does start to get full all you have to do is start playing with it like silly putty! (Which is fun anyway.) It doesn’t wear away, and you can use it for a long time before having to replace it. It even helps to clean off your hands as you knead it!
To find one, you can search Prismacolor Kneaded Rubber Eraser on Amazon, or check at your local art store.