Our series of IRT and IRT-S orifices are made of FDA Polycarbonate resin. 2 barb sizes and 1 non barbed sizes are available; 1/16 (5/64 inch) straight shaft; IRT-S, a 1/16 barbed and a 1/8 barbed orifice IRT 1B and 2B. The operating pressure is 100 psi with a repeatable flow of 3% plus or minus. 1/16 and 1/8 barbs have a stainless pre-filter to protect the orifice.Available in seventeen different color-coded orifice sizes as follows: 0.003 is Gold, 0.004 is Purple, 0.005 is White, 0.007 is Yellow, 0.008 is Light Green, 0.009 is Lavender, 0.010 is Light Blue, 0.012 is Dark Green, 0.014 is Orange, 0.016 is Gray, 0.017 is Brown, 0.019 is Red, 0.020 is Dark Blue, 0.025 is Black, 0.030 is Beige, 0.035 is Dark Gray, and 0.040 is Teal. Used to slow down air flow in applications in medical devices.