Here are the key differences between the Bosch GCL 2-50 G and the Bosch GLL 2-20 G (note: the specific model GLL 20-22 G is not mentioned in the provided sources, so the comparison will be based on the GLL 2-20 G):

## Laser Type and Visibility
- GCL 2-50 G: Uses green laser diodes, which are up to four times more visible than red laser lines, especially in bright environments.
- GLL 2-20 G: Uses red laser diodes.

## Working Range
- GCL 2-50 G: Has a working range of up to 15 meters without a receiver and up to 50 meters with a receiver.
- GLL 2-20 G: Has a working range of up to 65 feet (approximately 19.8 metres) in diameter.

## Self-Leveling and Precision
- GCL 2-50 G: Self-levels in less than 4 seconds and compensates for surface irregularities of up to ±4 degrees with a precision of ±0.3 mm/m.
- GLL 2-20 G: Self-levels with an accuracy of ±3/16 inch at 30 feet (approximately ±4.8 mm at 9 meters) and also compensates for surface irregularities up to 4 degrees.

## Additional Features
- GCL 2-50 G: Includes features like Bluetooth connectivity for remote control via an app, a motorized multifunctional mount, and automatic detection of the optional LR 7 Professional receiver.
- GLL 2-20 G: Does not have Bluetooth connectivity or a motorized mount. It includes a BM3 positioning device and various mounting options.

## Durability and Protection
- GCL 2-50 G: Has an IP64 rating, rubberized housing, and recessed front glasses for protection against impact, dust, and splash water.
- GLL 2-20 G: Has an IP54 rating, indicating slightly less protection against dust and water compared to the GCL 2-50 G.

These differences highlight the distinct features and capabilities of each laser level, making them suitable for different user needs and environments.