Does your film BLOCK all RF?

Percentage is an incorrect depiction of RF attenuation and is very deceiving. Every 3dB you cut a signal power in half.  So, anything over 21dB is “greater than 99%” reduction.  But 99% is not necessarily a high amount of reduction…it takes about 100dB to prevent a cell phone from connecting to the tower

Note that window film is only going to attenuate RF at the glass, and not the window frames, walls, etc., or stop any conduction through metallic penetrations or other conductors. An RF test is recommended to determine RF sources, power levels and if additional RF products are required