[Super Bleeder!!]

via wikipedia:

LS1 and onwards engines (as well as others) use a "coldwire" MAF system (produced by AC Delco) where the inductance of a tiny sensor changes with the air mass flow over that sensor. The sensor is part of an oscillator circuit who's oscillation frequency changes with sensor inductance; hence the frequency is related to the amount of air (CFM) passing over the unit. This oscillating electrical signal is then fed to the car's ECU. These MAF units (such as the one pictured) have 3 pins, +, - and F, the F contains the square-wave frequency between - and F.

The mesh on the MAF is used to smooth out airflow to ensure the sensors have the best chance of a steady reading. It is not used for measuring the air flow per se and it is not recommended that you "clean" these units other than ensuring the wire-mesh is completely flat and free of any debris. Manufacturers claim that a simple but extremely reliable test to ensure correct functionality is to tap the unit with the back of a screwdriver while the car is running, and if this causes any changes in the output frequency then the unit should be discarded and an OEM replacement installed.