energy-saving power strip
A power strip with features to reduce standby power consumption, such as master/slave outlets or timers.
省エネタップを使うと、待機電力をカットできます。
Using an energy-saving power strip can cut standby power.
Compound of 省エネ (abbreviation of 省エネルギー, 'energy saving') and タップ (from English 'tap', meaning a power strip or outlet adapter).