The SPRL-V1 is a three/four way fuel selector offering left-off-right and both if required.
There are 90 degrees between selections and the absence of a lower fitting reduces the depth required.
The SPRL Valves, as designed, have a very nice 'feel' and are logical in use, however, there is a requirement in FAR 23 whereby the fuel valve must be turned from OFF to an ON selection simply by turning it, i.e. it should not have to be lifted up, pushed down etc, and it should also not be possible to turn it from an ON position to OFF without a dent. See valves with a 'conforming' selector.