Cho
CHO - is an acronym that stands for Control Head Only. This means you get the unit itself , usually the hardware to affix it to your boat but no transducers or any other hardware.
Often used as a selling gimmick so the seller has the lowest price on search engines. It is not totally useless though as some can save money.If they are willing to do a little searching for the necessary parts. Or sometimes the buyer wants an extra unit for one transducer.
Garminarmin gpsmap 1040 xs networked with Garmin gpsmap 1242 xsv , Panoptix PS 30 and PS 31. Livescope LVS 32
Ice rig Echomap Ultra 106SV with LVS 12 and GT10-IF