The original Rev 1 Lens Unit required a lens removal tool to unscrew the lens retaining ring for lens cleaning.
The Rev 2 Lens Unit allows the lens to be removed far more easily by hand.
See the pics below to help determine which lens unit is installed in your machine.
![](https://darklylabs.com/wp-content/uploads/2021/10/IMG_2014-1024x808.jpg)
![](https://darklylabs.com/wp-content/uploads/2021/10/IMG_2015-1024x517.jpg)
![](https://darklylabs.com/wp-content/uploads/2021/10/IMG_2016-1024x897.jpg)