computer accessories, small household appliances: https://allegro.pl/oferta/rayovac-extra-312-emf-pr41-baterie-sluchowe-60-szt-8360257712

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)

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: OFF to 90db,
built-in magnet,
application: kitchen, science, training, office and many others,
power supply: 3x LR03 / AAA (not included)

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)

• 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

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

• Small, compact aluminum alloy housing
• support for USB-C PD power supply up to 100W port
• HDMI 4K 60Hz
  
• microSD and SD card reader
• 2 x USB 3.0 - speeds up to 5Gbps
• USB-C - speed up to 5Gbps