Review on BESTEK 200W Voltage Converter 100-240V with 4-Port USB Charging - Universal Travel Charger for All Countries to US (White) by Josh Lewis

I've seen many different voltage converters in different ranges (e.g. 25W to 2000W). This one was in the sweet spot with enough power to run 2 or 3 things I need (like a sewing machine and charger) without paying too much. There is a slight hum of its own during operation, which is a disadvantage. But I'm pretty sure it's just a consequence of what's happening with electricity. I've never used a totally silent step-up transformer. Since it makes some noise, I usually only use it when needed. So USB ports don't do much. Unlike the silent 4-port USB charger, which I can leave on and active all the time, I turn it off when I'm not using the UK voltage ports.