Extruder for gearhead motor like http://www.phidgets.com/products.php?category=23&product_id=3317_1 or Makergear's gearhead.T1 extruder guidler - like the Greg's guidler, but enclosedT1 extruder for car v0.9 - Designed to mount on TrinityLabs rail.T1 extruder for car v0.9b - same as above, but with secondary guidler on the extruder body.T1 extruder v0.9 - same as the above extruders, but designed for a standard reprap carriage and not the rail.T1 idler - this is IDENTICAL to the Greg's guidlerT1 extruder for both nema 11 and nema 17 gearheads is the same as the 1st file, except it has a 2nd set of holes for a nema 11 gearhead.The extruders include holes intended to mount a 40mm fan aimed at the hot end.Select one extruder and one idler/guidler.The versions that mount to the car mount with M6s.Use a groovemount to secure a hot end.