You can measure the pressure on the septic blower Each blower is determined by operating pressure. When used in a septic tank the air flow pipe is clogged it will cause high pressure and the blower will generate heat and malfunction. In addition, if the pipe cracks or falls off the pipe, the blower diaphragm valve is damaged at low pressure. Low pressure will cause the oscillation to be greater than required and may cause malfunction. In order to confirm the state of the empty station, it is necessary to measure the pressure, but there is no pressure gauge for septic tanks, this product is the first septic pressure gauge for septic tanks. There are 4 button batteries included, but it is for testing operations. Not covered under warranty. Please purchase it for yourself when the battery runs out. Batteries Used: DC 1.5 V (4 button batteries L1154 batteries); How to Use: The 13 A (Φ18) blower can be connected and measured as is. The outlet is 20 A (Φ26) blower is 13 A - 20 A PVC (male diameter), please purchase a separate hardware store and measure it.