computer accessories, small household appliances: https://www.conrad.pl/pl/p/bateria-panasonic-br2-3agct4a-6-v-2400

no installation required - compatible with Windows 8.1, 10, 11 
bluetooth version: 5.0
support for up to 7 devices at the same time
dimensions: 7 x 16 x 24 mm
range: up to 20m
Application: Keyboards, Mice, Headsets, Speakers, Printers, Modems, Phones, Xbox, Raspberry Pi and more

all cables in place and always ready for use,
easy to install and use,
strong and safe magnets,
flexible silicone tips

small compact housing,
Supports up to 4 devices at a time
high performance - 1xUSB 3.0 + 3xUSB 2.0,
delicate LED ring indicating the operation,
power supply can be connected (micro USB connector)

elegant and stylish - large backlit display,
intuitive operation - rotating ring,
3 alarm sound levels: OFF to 90db,
built-in magnet,
application: kitchen, science, training, office and many others,
power supply: 3x LR03 / AAA (not included)

support for resolution up to 4K (3840x2160) @ 60Hz
LEDs to indicate the operation of the device

elegant and stylish - large backlit display,
intuitive operation - rotating ring,
3 alarm sound levels: FROM OFF to 90db,
built-in magnet,
adjustable stand 0° - 80°,
application: kitchen, science, training, office and many others,
Power Supply: 3x LR03/AAA (not included)

• Bluetooth version: 5.3
• Range [m]: up to 20
• Compatible protocols: A2DP, HSP, AVRCP, HID
• dimensions [mm]: 7,5 x 16,2 x 28,6