IDA-71
Another Russian military rebreather. But adapted for civilian use. This unit also required all its old cylinders (o2 and the offboard nitrox tank), plus its gas pneumatics basically stripped out and binned. Again, much simpler to make use of a kiss valve. Back in the day, Dave Sutton did his Franken Rig teardown on his own unit, which inspired me to do mine, in fact I've done 2.
o2 is fed via a needle valve/manual bypass into the counterlung, as is the offboard diluent via its inbuilt ADV. The ADV sits on top of the rebreathers casing and into the 7 litre capacity counterlung. Breathes 'ok' providing you upgrade the DSV and breathing hoses. I used good 'ole Drager Ray bits. PPo2 monitoring was added via a P port directly into the counterlung close to where diluent is injected to keep moisture on the cells to a minimum. The 'stock' DSV is really well made, but work of breathing through it is poor. This conversion was the most annoying, and arguably more trouble than its worth. Bail out is worn offboard rather than trying to squeeze in a 2 litre cylinder.