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Inline outlet-gang box transformer
$30
Small format - designed to replace an outlet near the shades and fit in a standard electrical gang box. Input terminals are household power (120 VAC), outlet wires are 12VDC and 2 amps. The wires can then be extended to your shades, and the outlet box is closed with a cover blank, commonly available. Power up to 4 average size Leviosa shades, daisy-chain wiring them together. Leviosa can provide wire splitters and hard-wire connectors.