> 「車載卡」外形及大小與電子手帳相若，以雙面膠紙牢牢黏在車廂內的車頭玻璃上，儀器背部螺絲位更蓋上保護貼，防止有人私下拆開儀器。
Yeah, a card without any power sources is likely to transmit audio up to 20 km (~12 miles) away
Yeah, a card without any power sources is likely to transmit audio up to 20 km (~12 miles) away
Something like "The 'car card' is about the same size and appearance as a PDA (?), it's tightly stuck to the inside of the front car window with double-sided tape, the screw holes in the back of the device are covered with protective stickers to prevent people secretly opening it.". Doesn't address the power issue at all as far as I can tell.