I purchased this extruder to replace the one on my Geeetech A30T. This is much nicer due to the metal case and ergonomic design. I can now load filament without bruising my fingers from the old one. It has a 3:1 ratio gear like my old one but this has an extra idler so it should be better with TPU. The seller is excellent. I had a problem with one of the brass gear and was immediately sent a replacement with speedy delivery. A+ seller.