The passenger door and observation door are installed at the intermediate height of door.

行人门及观察窗在门扇的高度上居中；

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The observation window on the door is made of double-layer tempered glass, the material heated in the oven can be observed clearly, meanwhile, the thermal insulation is well.

箱门观察窗为双层钢化玻璃结构，能清晰观察箱内加热的物品，又有良好的隔热效果。

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There's lighting inside the case and sight window on the outside door, convenient for observation.

两个玻璃观察窗位于给料机进口端（端门），用于观察胶带运行状况。

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At Devens, he is locked inside a 10-by-10-foot cell with a steel door, a slot for food and an observation window, a prison spokesman said Sunday.

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