The easiest way to get a refill for your pen is to call Elliot at 1-530-795-2648. I'll charge you less and send the correct refill directly to you.
But if you like to get things yourself:
What kind of pen do you have?
Desk ballpoints: (#001,#101, #PSE, #SHS)
These are long pens that don't retract and don't have a cap. Use a "Cross type" refill purchased at a place like Staples or Office Depot, but don't use an actual Cross refill. Pull off and discard the plastic cap on the non-writing end of the refill, and you now have the refill you need for these slender pens. A. T. Cross Company started gluing on the plastic cap in 2001, which is why these can no longer be used.
Twist Ballpoints (#202S, #203S, #204S)
These are ballpoint pens that retract by twisting the pen. They use a Cross or Cross-type refill, which is easy to find at office supply stores like Staples and Office Depot. You refill the pen by pulling the pen apart -- it separates in the middle.
Rolling Writers
We currently make two types.
The #RWS has a cap that pulls off, and the clicker has a push button action. Both pens use the Pilot G2 refill, that is usually available in stores like Staples and Office Depot.
Fountain Pens
Our fountain pens use European style refills like those made by Mont Blanc and Pelikan.
We warranty the items we make and we will replace or repair anything you send us.