I (somewhat) recently upgraded to a Ubis 13S hot end after having several Ceramic ones fail on me. I've been extremely pleased with the hot end, but less than pleased with having to use the old-style, very directional, fan shroud, since the one I preferred wouldn't fit the Ubis 13. Being anal-retentive, OCD, and a little masochistic, I decided to design my own. This duct is designed to move mount the fan on the outside of the frame, instead of inside. This allows for the use of whatever "depth" of cooling fan you'd like. I'm currently running a 20mm fan, which seems to work pretty well for PLA. Two versions of the STL are provided - one with a small support on the "back" of the exhuast side of the duct, and one without. I prefer to print mine using the supported version, and also with Cura-generated support material, but just touching the base - otherwise you get support material up inside of the duct that would be a booger to get out. I've got a fair number of prints run on this one now, and I'm pretty happy - previous versions were too close to the bed, but depending on your printer setup you may have to do a little trimming.