A 30-square-meter clothing store uses 10- 15 40-watt spotlights. Generally, a 30-square-meter clothing store can use a 40-watt spotlight of 10- 15, which looks like the store will be more upscale and consume less electricity. Under the same brightness, the power is equivalent to 40% of metal halide lamp, saving 60%. So a 30-square-meter clothing store uses a 40-watt spotlight 10- 15.