Hamilton 84301 CR-700 20µL CR700-20 Constant Rate HPLC Syringe with 22g x 2" x PT3 Needle has preset volumes that can be dispensed at a constant flow rate. The volume is adjustable with a precise adjustable micrometer screw. The adjusted volume can be fixed with a locking ring. Reproducible injection speed is obtained by means of a spring. The sample is delivered by pressing the push button. All of these features make the syringe easy to use. Typical applications include carbon analysis and analysis of waste water.