This is something very cool. If you have an AeroPress, this little attachment replaces your filter and also serves as a pressure-activated valve so you can more closely approximate the process of creating espresso. It also eliminates the need to brew with the often tricky and scary (OMG!) “inversion method” because it’s valve stay tightly sealed until you apply pressure — no drips! Plus, you can also use it to shoot hot coffee at your friends (not recommended). At $25 its around the same cost as an AeroPress itself, but well worth it given all of the added features. Ours is on order and we will review it shortly.