Waters Alliance Series 3-Column Select Valve Kit, is an accessory designed for Waters Alliance HPLC Systems. It enables automated switching between up to three HPLC columns, increasing method flexibility and throughput without manually reconnecting column plumbing. The kit supports automated selection of up to three columns for method development or multi-method workflows. Includes an 8-port 3-column select valve assembly (P/N 279000614), PEEK tubing, compression screws, and restrictor tube assembly for installation.