C.B.S. Scientific offers 8 different sizes of linear gradient makers with side outlets. Gradient flow is controlled by a PTFE® valve centered between the two chambers. The outflow channel is fitted with a male luer adapter which can be used with any needle or luer valve. The smaller gradient makers have a support rod for attachment to a ring stand. Available in sizes of 10ml, 20ml, 50mls, 75mls, 100mls, 250mls, 500mls, and 1000mls per side.