Kit includes 2 Microtight unions, 2 Microtight adapters, and various Microtight tubing sleeves. The kit includes 10 each of 8 sizes of Microtight tubing sleeves, ranging in I.D. from 125?μm - 530?μm (color-coded). The appropriate sized tubing sleeve has an I.D. 0.002?in. to 0.003?in. greater than the O.D. of your tubing.