These scales have a shock proof metal housing with high quality steel hooks the adjustable dial and scales are very accurate the dial has a plastic protective cover advice on adjusting the scales 1 the upper screw is only screwed on by 50 2 please release the 4 screws at the top of the scales 3 lift glass face and adjust the needle by hand to approx 0 kg 4 sometimes it is necessary to pull the screw which holds the needle 5 put the glass face back on the scales and screw on the 4 screw