Free 

The pin has grooves in each end for a clip to keep them from sliding out. It is flat on one side to make it easier to print. The clips are described below.
"Wire Spring Hose Clamps, 32 Pcs for 4.5-4.8mm OD 0.16"(4mm) ID 304 Stainless Steel Spring Clip Pipe for Fuel Line Silicone Vacuum Air Hose Tube Water Pipe, Silver" from Amazon to clip into the two grooves. I've attached a link for the Amazon part.
https://www.amazon.com/dp/B0FDWKNVCF?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1












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