Intelligent Filament Runout and Jam Detector Mk.2br br Does NOT return False Positives. (Long time tested, many 3D Prints many months)br br Using an Idler Wheel instead of Dual Gears does NOT return False Positives.br br Many, many Hours , days, of 3D printer testedbr br STL files:-br br Does NOT return False Positives.br br Two other bearings MR85 (5 x 8 x 2.5)br br 5 and 3mm bolts and nuts.