Ideal for common mode chokes or RFI power line rejection. These large internal diameter (25.15mm) clamp on cores are ideal to help remove RFI through mains power leads and other sources.
 
Real world example of using these cores to clean up main power can be seen at https://gm3sek.com/2019/10/11/clean-up-your-shack-2019/
 
Part Number: Fair-Rite 0431177081 mix 31 split cable assembly
 
Lower & Broadband Frequencies 1-300 MHz (31 material)
 
Typical Impedance (Ω)
1   MHz        50
5   MHz        121
10  MHz+    146
25  MHz+    218
100 MHz+    356
250 MHz        404
 
Internal diameter through hole of 25.15mm maximum.
 
Ideal for common mode chokes or RFI power line rejection.