Sonoff RL560 RJ9 4P4C sensor extension cable, 5 m

Length of the cable from the adapter body to the plug. For a detachable cable, the length of the supplied cable is given.

How far from the relay or controller the sensor can be placed using extensions, per the maker. The limit can depend on the sensor type; this is given in the note.

Whether extensions can be joined one after another to reach the length you need. The total is still capped by the maximum total length.

Whether the maker allows plugging and unplugging the extension with its sensor while the device stays powered. If not, connect them with the power off.

What the cable's outer jacket is made of. PVC is the usual jacket for indoor use; silicone withstands higher temperatures; UV resistance for outdoor use is stated separately by the maker.

The device’s weight without packaging, per the maker.

The connector type at the cable's ends. It must match the device's socket and the sensor's plug: RJ9 and RJ11 look alike but differ in width and number of contact positions.

The sensors the maker allows to be connected through this extension. A matching connector alone does not guarantee it works: different sensor types tolerate long cables differently.

The devices whose socket the extension with its sensor plugs into — e.g. relays or thermostats with an external-sensor input.

A plug-to-socket extension fits between the sensor and the device without adapters. A plug-to-plug cable joins the sensor through a separate coupler.

How many conductors run inside the cable. There must be at least as many as the contacts the sensor uses; an RJ9 4P4C connector has four.

The electrical resistance of a conductor over the cable's full length in ohms (Ω), per the maker. The lower it is, the less signal and sensor supply is lost over a long run.

The housing colour of this model. Other colours in the same series are separate products.