This is the first item's accordion body. Cobham SAILOR 6217 VHF DSC Class D AIS Receiver is waterproof to IPx8 and IPx6, you will experience the SAILOR resilience and ability to perform in any condition at a highly competitive price point. Premium, rugged quality for less, regardless of your vessel type: Work boats, fishing vessels, super yachts and ships can all enjoy reliable DSC communications out on deck or at the helm. Building on SAILOR 6215 VHF DSC Class D, SAILOR 6217 VHF DSC Class D AIS Receiver integrates a two channel parallel AIS Receiver, which enables it to perform a constant watch of both AIS channels, rather than switching between them. This provides greater safety through better situational awareness, because you get a seamlessly updated view of AIS equipped vessels in the surrounding area at all times.