With the Signature M650 series, Logitech offers a wireless mouse that is available in different sizes and also in a left-handed version. The mice are already compatible with the Logi-Bolt technology and have a comfortable SmartWheel.
https://www.notebookcheck.net/Logitech-Signature-M650-review-Wireless-mouse-with-bolt.596498.0.html
Can I pair this mouse with another USB dongle if I lose/broke the original one?
This feature(Unify) is perfect.
I found the answer.
This mouse cannot be paired with another USB dongle. Only a mouse with bolt logo on the bottom side can be paired with another (bolt) USB dongle.
Sorry. My previous answer is wrong.
This mouse can be paired. There is a bolt logo so this mouse ca be paired with another bolt USB dongle.
Bolt vs Unifying logi devices: as incompatible as oil and water.
They do not mix at all.
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The Logitech Signature M650 (with Bolt) can pair with any other USB Bolt dongle.
Any USB Bolt dongle can pair with six (6) Bolt compatible devices as of this writing (info from Logitech Options software).
HOWEVER, this entire Bolt ecosphere of mouse/keyboard/Bolt-USB-dongle is incompatible with the older (legacy?) Unifying mouse/keyboard/USB-Unifying-dongle.
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For example, my MX Anywhere 3 with USB-Unifying-dongle can pair with any other USB Unifying dongle.
Any USB Unifying dongle can pair with six (6) Unifying compatible devices as of this writing (info from Logitech Options software).
HOWEVER, this entire Unifying ecosphere of mouse/keyboard/Unifying-USB-dongle is incompatible with the newer (replacement?) Bolt mouse/keyboard/USB-Bolt-dongle.