M1 are with adjust bar (at the bottom of the weights), F1 are without. Buyers are responsible for these charges. B, If you can not ensure it. Do not share any information with third party. The item "F1 Grade 1kg-5kg Precision Stainless Steel Scale Calibration Weight Kit Set my#" is in sale since Wednesday, December 20, 2017.This item is in the category "Business & Industrial\Healthcare, Lab & Life Science\Lab Equipment\Lab Scales & Balances\Weights & Calibration Sets". The seller is "mywelllife" and is located in ShenZhen. This item can be shipped to United States, all countries in Europe, all countries in continental Asia, Canada, Australia.