The DR900 Vacu-vials® Adapter is required to use CHEMetrics Vacu-vials® ampoules with the DR900 colorimeter. This adapter is used in conjunction with the 16 mm adapter originally supplied with the DR900. Simply insert the Vacu-vials ampoule into the 16 mm adapter and slide the CHETA-0215 over the ampoule. The CHETA-0215 will center the ampoule and act as a light shield.