The CVS4200D is a discrete, stationary water sampler designed for indoor use. Each sample is placed into a separate container. The sampler uses reliable, long-lasting, vacuum technology. This sampling method results in faster sample draws and less disturbance of the sample contents. There is also less wear on the tubing, resulting in less frequent maintenance. The CVS4200C differs from the CVS4200D in that it is a composite sampler, with all samples combining into a single container.  Vacuum technology benefits over peristaltic pump samplers: Accurate sample volumes Rapid transport velocities mean more-representative samples Less disturbance of sample Minimal wear on the tubing, resulting in less-frequent maintenance Reduced cross-sample contamination