Lezyne KTV2lightsrubber bung to cover the USB (Universal Serial Bus) port for both front & rear lights. If you need areplacement as you have lost yours, cheap & original Lezyne spares from Cycles UK. Rubber press in bung, which covers the USB (Universal Serial Bus) plug, for the Lezyne KTV2 Front & Rearlights. The KTV V2 bung fits the newer Y10 KTV2 lights as pictured. Picture of KTV2 Lightset isfor representational purposes only.