GREEN packaging identifies the TRACOE twist plus product family. A further colour, such as BLUE with a "+" sign in the example, indicates a cannula type, here the REF 312. The + helps differentiate between the two twist families. This colour coding represents the cannula's special characteristics. You can see all colour codes and their meanings below.The families/types can be sorted according to these colours. The size of the cannula is indicated at the end of the REF number, for example REF 312-08 for the size 8 mm.The colour coding makes stock keeping easier.