This is Airtripper's Bowden Extruder Modified to hold a push fit connector.Purchase pushfit connectors: (one for your extruder body, and other optional one for the hotend) http://www.amazon.com/gp/product/B004M8T2JG/ref=oh_details_o08_s00_i00 See https://groups.google.com/forum/?fromgroups=#!topic/deltabot/LtLlZtANu4s for alternatives. The units I purchased were less than $3. MC KQ2S04-M5 PBT Push-To-Connect Tube Fitting, Hexagon Socket Head Adapter, 4 mm Tube OD x M5x0.8 Male These push fits and other 3D printing accessories available here as well: http://www.tridprinting.com/Hot-Ends/#3D-Printer-Push-Fit-Fitting Also note: Jasper has an alternate one: http://www.thingiverse.com/thing:33342 http://reprapworld.com/?products_details