Sonoff SPM-Main Smart Switch Wi-Fi/Ethernet Power Meter Sonoff SPM-Main smart switch that allows you to measure power consumption. The device is the main element of the system consisting of SPM-Main and SPM-4Relay. The device supports wired (RJ45 Ethernet port) and wireless Wi-Fi connectivity. The product is very versatile - it supports up to 128 channels! To do this, connect it to the SPM-4Relay switch (max. 32 pcs). SPM-Main is equipped with overload protection to avoid damage to your devices. In addition, thanks to the built-in microSD card reader, you can protect energy consumption history from up to 180 days ago! Specification: Producer: Sonoff Model: SPM-Main Color: White Input: 100-240 V ~50/60 Hz 50 mA max. Wi-Fi: 802.11 b/g/n 2.4 GHz Material: PC V0 Dimensions: 142.5 x 90 x 66.5 mm Compatible microSD cards: 8-32 GB (microSDHC)Key features:Many applications - The SPM-Main switch has many different applications - it allows, among others: checking how much electricity your tenants use monthly, what is the energy consumption in your office, protecting expensive equipment in the server room - the switch has overload protection.Possibility to connect devices - SPM-Main communicates with the cloud via an RJ45 Ethernet port or Wi-Fi. Connection to SPM-4Relay switches is made via the RS-485 port, which ensures stable transmission over long distances.Support for up to 128 channels - One SPM-Main main module allows you to connect and control up to 32 SPM-4Relay switches. Each SPM-4Relay offers as many as 4 independent channels with a maximum load of 20 A each. Thanks to this, SPM-Main can handle up to 128 channels! This makes it an ideal solution for apartment blocks - it allows you to check energy consumption in 128 apartments.Energy consumption history on the microSD card - The product allows you to save the history of energy consumption measurements from the last 180 days. The switch is equipped with a microSD card reader (8-32 GB, microSDHC). This allows you to conveniently export data and ensure that important information is secured.Note: microSD card and SPM-4Relay are not included.