What is the fine-grained topic of the following text: 6pc 100g 50g 20g 10g 5g precision calibration scale weights balance test set kit smooth surface the tweezers is convenient to hold all of the weights for quick easy access permissible error +/- 0.003g quantity 1 x 100g, 1 x 50g, 2 x 20g, 1 x 10g, 1 x 5g color silver total weight250g. Only return the topic.
Precision Calibration Scale Weights Set