For those looking for an additional attitude indicator that can be installed “anywhere in the panel”, then the uAvionix AV-30-C could be an option (at least for GA aircraft). The AV-30-C may be installed in most GA aircraft using an existing EASA AML STC. The unit fits in a standard 3 1/8″ hole but the maximum 6-32 screw length protruding the unit is limited to 3-4 threads?!! Initial startup indicated a failed battery right out of the box but after an hour or so and after several restarts it seems that the battery came back to life, started to charge and finally got to 100% charge. The D-Sub connector included in the installation kit including the back shell made out of plastic, possibly the cheapest uAvionix could find? The installation manual states that the unit is factory calibrated to highest standards but our unit displayed 48kts when the test set Barfield, Aspen E5 and analogue ASI were almost spot on 40kts. The altimeter was of by about +30ft or so. This unit is not TSO’d (technical standard order) but should be equivalent as it is approved for installation in certified aircraft. We were able to “adjust” the ASI and altimeter to be within spec’s. Now its time to hand over the instrument for real world flight testing and see what the owner’s think.