... the video format, include PAL, NTSC, SECAM, compatible with post, real time transmission if no delay, multi-channel are aluminum alloy shell ... °CHumidity:0~95% (non-condensable) NA300A/NA600A:wireless 300m/600m video transmitter receiver NA600A4: 4 channels wireless 600m video transmitter receiverNA600A16: 16 channels ...