[OneCosmos (Chris)]

The Airylab SSM Ibelieve is either no longer available or, if listed, out of stock and possibly out of production.

Gif any solar imager this is an extremely useful ‘seeing conditions’ monitor with a real time graph and associated Windows app to show how good seeing is.

Using this device, you can check instantaneously the seeing value in arc seconds at your specific location
Shows instant seeing value, light input and 1 minute moving average
Separate sensor can be placed next to the entrance pupil of your instrument
Runs on battery or USB

$500 firm