Over time, research in ground water monitoring methods has brought about improvements in sampling methods including the development and implementation of low-flow purging and sampling protocols and, more recently, passive sampling techniques such as use of the Polyethylene Passive-Diffusion Bag (PDB) sampler. Passive sampling techniques are based on the concept that there is continuous natural flow through in well screens. Where the use of passive sampling is appropriate, the use of passive sampling can result in cost reductions and in some instances, improvements in data quality. Passive sampling methods include the use of diffusion samplers (such as the PDB sampler), sorptive samplers (such as the Gore Sorber Module), and the use of equilibrated grab samplers (such as the use of the HydraSleeve and Snap samplers). Equilibrated grab samplers are typically left in the well for a period of time following deployment. This equilibration period allows for the well to recover from any disturbance made by placing the device in the well and allows time for the device to equilibrate with the analytes in the well water. This paper will present the results from several laboratory and field studies conducted to evaluate these two equilibrated grab samplers, i.e., the Hydra Sleeve and Snap samplers. Laboratory studies have examined the ability of these devices to recover representative concentrations of VOCs and explosives (when compared with known concentrations of the analytes) and the equilibration times needed for these devices. In addition, holding-time studies have been conducted on VOC samples in the Snap Sampler bottles. Field studies have examined the ease of use of these samplers and the ability of these samplers to recover representative concentrations of volatile VOCs and explosives when compared with concentrations of these analytes taken using low-flow purging and sampling.