Is there anything better than a beautiful ink all cooped up in a gorgeous, weird-looking bottle? Why, yes. yes there is. There is, because eventually you will get only halfway to the bottom of that crazy big bottle of ink you bought six months ago, and you won’t be able to suck it up into your pen, no matter HOW HARD YOU TRY!!! Never fear, dear Pen Lover! TWSBI has your back! You can use this wonderful, ingenious inkwell no matter what sort of ink or pen you want to fill. Just pour your ink from that pretty but useless confection of a glass doorstop into THIS inkwell, screw on the cap with the internal little plastic bit in place, flip it over, uncap the inkwell and voila! You can suck that gorgeous ink right up in to your pen. There is a special way to use it with your Diamond 50, but so far, I’ve used it on other pens. It is ‘way more stable than that little cheap plastic “ink miser” you can get on Amazon. I don’t warry about tipping this sucker over. It is like the Rock of Gibraltar, sitting there on my desk—if the Rock of Gibraltar was 3 inches tall and made of glass. Five stars. I have two. The other one works just like this one. this is the fountain pen appliance you didn’t realize you needed. Get it.