25pcs 1mg -1kg Class F1 Calibration Scale Weight Kit Set 304 Stainless Steel. F1 Grade 1mg-1Kg Stainless Steel Calibration Weight Kit. F1 grade 1mg-1kg stainless steel scale calibraiton weights kit sets, balance weights. Total 25 pcs weights, use 304 stainless steel. Packed in aluminium alloy case.What's the difference between our F1 and M1 Weights. F1 are more precise than M1, with smaller permission error. F1 use 304 stainless steel, M1 use 2cr13 stainless steel. M1 are with adjust bar (at the bottom of the weights), F1 are without. Feedback is very important to us. It is impossible to address issues if we do not know about them! Faction is our ultimate goal. We work hard to earn your trust and future business. A If you receive a defective item, you may return it or ask for a discount. Due to time zones, our reply to your questions may not be immediately. If it's non-workdays, please kindly be patient and wait till Monday. The item "1mg-1kg F1 Grade Stainless Steel Scale Calibration Weight Kit Set 25 pcs USA" is in sale since Wednesday, May 15, 2019. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical/Lab Equipment Attachments & Accessories\Calibration Weights". The seller is "yullstore" and is located in Rowland Heights, California. This item can be shipped to United States.