It was inevitable with selling these for years. Eventually rejects would accumulate. Mostly they have what appear like scuff marks where the 2 movable pieces slide against each other. Others are finished in a certain way that makes them look different so we can't sell them with the others. If it impaired their functionality, they wouldn't be listed online, they'd be recycled for the steel. Stainless steel with curved sharp tips, the discriminator allows the careful measurement in 3 mm to 10 cm. Point covers for protection when not in use.