Polyethylene plastic tubing 1/4" OD with a length of 21½ inches. The $16 price is for 50 pieces, as shown in photo #1.  Color grey. This tubing was a replacement part for the Aprilaire model 600 humidifier and used for water delivery to the humidifier pad.  Condition is brand new, never used.

This tubing does not have a PSI rating printed on the tubing but I tested several of them with compressed air and they would hold 160 psi at room temperature, that is the maximum of my compressor (see photo #2).  Shipped in a blue poly bag as shown in photo #3.  Weight for the 50 pieces is 1 lb.