This technology has been in existence for many years. It is typically used in lower point count situations due to mechanical stress situations caused by probe forces and the lack of vacuum. The UUT is isolated from vacuum, and the lid provides the counterforce needed to overcome the probe forces. These gates will keep probes in a cleaner condition because there is no contaminated air being pulled across the probes at actuation. We recommend this lid for applications of less than 1000 probes.