Macro Stir Bars are single use, plastic coated stir bars for use in stirring Platelet Rich Plasma samples during incubation and testing. Macro Stir Bars are for use with the PAP-4 Series Platelet Aggregation Profilers using Macro Test Tubes.DisposableFor Use with the Siliconized Macro Test Tubes (C/N 100336)For Use with PAP-4 Series Aggregometers