I designed this because I noticed issues with the PTFE tube going into the hot end. When printing larger pieces where the hot end has to move towards the limits of it's travel, especially in the corners, the tube really pinches and can cause binding on the filament. The standard led riser helps, but doesn't go quite high enough. I replaced the PTFE tube with a slightly longer piece to allow the angle going in to be smoother and more straight. This riser allows ample “head” room plus adds additional functionality with built in vents that you can open and close without having to remove the top glass.
Vents use M3 x 10mm SHCS bolts with washers to mount to the main ring.
*** Note about the dovetail connections***
These are designed to be pretty tight. You will probably need a small block of wood and a hammer or mallet to tap them together. I just set the pieces on a nice flat surface and tapped together till the top is flush.