[TG11] B744VL transducer question

[jgj252]

Several online sites (Defender, for example) have this transducer for sale, and there are two versions commonly shown:

Part no. A66092
Transducer AND high speed fairing
"Compatible with DSM300, DSM30 and CP300"

Part no. A26044
Just the transducer
"Compatible with ST40, i40, ST60+, i50, ST290, ST70* and i70*"

Are they different, electrically? Or is the difference in compatibility only because those would be the instruments commonly used (low speed vs. high speed)? Or...?

(I have an i40 BiData, and want to know if I can buy the A66092 and stand a chance of it working correctly. It's available from one source at a discount, whereas the A26044 is not.)

Thanks for any info,
Jim