Electronic Whistles for Referees with USB Charging, 3 Tone High Volume Whistl…
Can keep sounding for 4 hours. USB direct charging save the cost of buying batteries. - Sport Electronic Whistle, 3-Tone, 120 dB, Specific Direction. It is perfect for referee coaches, P. teacher,, outdoor camping, sports competitions, traffic guides, pet training.
Electronic Whistles for Referees with USB Charging, 3 Tone High Volume Emerge…
Can keep sounding for 4 hours. USB direct charging save the cost of buying batteries. - Sport Electronic Whistle, 3-Tone, 120 dB, Specific Direction. Independent lithium battery were not sold with the product.