This extension lets you sample three feet deeper provided you have a ESP Sampling Tube and a JMC ESP Master Extension. Regular extensions connect to each other for additional sampling depth capability.
Threaded Guide Rod fits manual sliding hammer for both the JMC Environmentalist's Sub-Soil Probe (0.8 inch diameter sampler) and the JMC Environmentalist's Sub-Soil Probe Plus (1.2 inch diameter sampler).