F1 uses 304 stainless steel, M1 use 2cr13 stainless steel. M1 is with adjust bar (at the bottom of the weights), F1 is without. F1 Grade 1 mg to 1 kg, meeting most needs of the measurement. Includes 25 pcs weights, coming with aluminum storage case, plastic storage box for tiny weights, tweezer and cleaning cloth. Cylindrical shape, structural stability, resistance to corrosion, and low magnetic susceptibility.Can be used for balance scale, calibration of mini electroic scales, digital jewellery scale. Please read the Precautions in Product Description. We offer a 100% Satisfaction Guarantee on all sales. We will happily work with you to find a solution to any problem. As you can tell from our feedback, almost every customer is a happy one. Our goal is always a satisfied customer. It's Raining Deals 2. The item "Goetland 304 Stainless Steel Class F1 Calibration Scale Weight Kit Set 1 mg 1" is in sale since Monday, July 9, 2018. This item is in the category "Business & Industrial\Healthcare, Lab & Life Science\Lab Equipment\Lab Scales & Balances\Weights & Calibration Sets". The seller is "its-raining-deals-2" and is located in US. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Dominican republic, Panama, Trinidad and tobago, Guatemala, El salvador, Honduras, Jamaica.