IDA-72V is written IDA-72B in Russian. The IDA-72V is shown
here. "V" stands for Vodyanoj meaning "water heated". So the IDA72V
is umbilical guided and dived unit supplied with hot water and probably gas.
The bottles inside will offer redundancy.
IDA-72E is the Elektricheskij version, meaning
"electrically heated". The unit works in the same principle but received low
voltage electric power form the surface. The IDA72E was later modified for
the use of Heliox and called IDA 73