Hi, I am excited to share with you my updated bolt action pen design. I have just added a new pen size, making it compatible with even more refills! I designed this pen a few months ago as I wanted a 3D printable pen that worked and looked how i wanted it to. After a few updates to the design that fixed compatibility issues, print problems and added a whole new pen size, I am confident when I say the design is better than ever. I'd love to know what you think. Thanks!