Makerbot - Machined 1-piece PTFE Core Tube for MK6 1.75 mm
This is a new, single-tube version of the 1.75 mm coretube was designed to
enhance the performance of the MK6 and MK6+ Stepstruder when printing 1.75 mm
filament. It's a new, specially-machined, single-piece unit that increases
reliability with small-filament setups.