For price comparison's sake, the same model -- the PLA4215KIT -- is being sold at Amazon.com for $79.53. As a starter kit, it includes two modules. One, the source module, is hooked to your router and plugged into a socket (no power strips or surge protectors). Then, the "destination," so to speak, is plugged into another outlet in your home.
It will then connect and pair with the first module. The two will communicate, from then on, with encryption a possibility, as well (as an option).
Interestingly, Amazon.com has a ZyXel kit that includes a source module and a destination module with a Gigabit switch for $73.73, which is lower than the cost of this one (in terms of their prices, anyway). With the Gigabit switch users can expand the destination to include more devices. Of course, it's possible to simply add a dedicated switch to the destination module's output, instead.
The 4205 (with the switch) also does not have pass-through capability, meaning users will lose a wall socket. The 4215 -- the one advertised by 1 Sale -- has a pass-through power socket.
The 1 Sale kit includes two PLA4215 wall-plug network adapters, Ethernet cable, quick start guide, support CD, and a warranty card. According to the site, orders are expected to ship in 3 - 5 days.
Powerline networking, for those who don't know, works by routing the Ethernet signal through the power circuitry in your house. Note that there can be problems if the remote end and the originating end are not on the same circuit, but if they are, the speed and reliability is excellent.
These adapters advertise speeds of up to 500Mbps. Note the words "up to," however.
You should also be careful with selecting varying models of varying powerline adapters. For example, this model has a Gigabit Ethernet port. Meanwhile, some other models sold by ZyXel only have 100Mbps ports. Of course, that really doesn't matter that much if the transmission through the powerlines doesn't hit 100Mbps, anyway.
A lot depends on what shape your home's wiring is in. One user, commenting at Amazon.com, measured his transmission rate at 20Mbps.
The theoretical maximum channel data transfer rate is derived from IEEE 1901 specifications. Actual data transfer rate will vary from network environment including: distance, network traffic, noise on electrical wires, quality of electrical installation and other adverse conditions.