KT600 english manual paperless recorder / Recorder U means to have the interface of USB. S means to have the interface of an SD card. The interface doesn’t need extra money, but if need the SD card, extra money is 50$. Pls, check the attachment user manual of the KT600 series. https://www.slideshare.net/MichaelSun5/kt600-eng-manual-paperless-recorder Share This Story, Choose Your Platform! Contact Us Please prove you are human by selecting the truck. Request a Quote