This is a mount rail I made a while ago with a 3D printer. I believe I tried to attach it to a Nerf gun using double-sided tape. The ruler is not included. Please check the images. I have not removed any burrs. Since it's 3D printed (PLA), it's not very strong. There are no burrs removed, and I don't know if the rail width will work, so please check the images again and consider before purchasing. Shipping will be on weekdays, excluding weekends and holidays. It will be sent via Mercari delivery with simple packaging. Instant purchase without comments is okay. Thank you.