I picked these up off a website called Dew Drafting Supplies for $1.29 per package. That's six LONG erasers for $1.29, and I'm not sure they did it, but I got three packages (18 long erasers) for about $3.87. shipping was about $5. I've been looking for these because the majority of new erasers I could buy for a Pentel P200 series are the shorter ones. To find them, I did a Google search for Pacific Arc ers-3 eraser. I have some joy now. Hopefully they don't rot out on me before I can use them all.
Soo, I have used these erasers before, and they work well. They feel about the same as the Pentel erasers, except I think they are a tiny bit larger. What that means, is the long Pentel erasers for the P205 slides in nicely, the Pacific Arc ERS-3 eraser is kinda snug. Not hard to put in, but snug. It erased well. I recommend these if someone is looking for a longer eraser for a Pentel P200 mechanical pencil. If you have the original Pentel erasers for the p200 series, I would just use those. But these make a fine replacement IMHO. And inexpensive too.