This blower is being used to displace/replace air in a large sewer vault that has a hazardous atmosphere. Our crew was using an 8" manhole blower, but it wasn't able to replace enough air to make the confined space safe for entry. This blower has a much higher output with two speed settings and it works as intended. It also has a GFCI plug for added safety around wet environments. We expect the blower will see a lot of use around the sewer district. So far, we are very pleased with the product.