This is W1JR BalUn, it can be used as 1:1 Line Isolator or 1:1 Current “Choke” Balun. Works well from 3MHz to 30 MHz.
Works very well from 5MHz to 15MHz. Can handle 1KW CW/SSB and 500W FT8. Made of RG-400 PTFE coax and FT240-43
ferrite toroid. You will get what is pictured.