Notch filters are designed to knock out specific bands of radio interference. They have significantly lower loss than high pass, low pass, or band pass filters and often have higher than 20db choking capability.
The 433/1.3 filter is used on your UHF radio when flying on 1.3GHz video.
Reject band: 1220-1360MHz
Filter strength: 24db
The 1.3/2.4GHz filter is used on your 1.2/1.3GHz video transmitter when flying on 2.4GHz control.
Reject Band: 2300-2550 MHz
Filter strength: 26db