Measuring a bicycle chain's pitch can be used to identify chain wear and flag the need for a replacement chain and/or cogs and chainrings. Bicycle Chains: Length, Width, What's Best to Buy etc.
An industrial, or scaffold, piercing is made up of two holes that are connected by a single piece of jewelry (usually a long barbell). An industrial piercing is commonly made through the cartilage on the upper ear, with one hole close to the head and the other further down on the outer rim. Two or more industrials on one ear is sometimes referred to as an ear cage.
Search for a sophisticated piercing studio that offers high standard facilities. Since daith piercing is a bit complicated, it must be carried out by an experienced piercer. After initial cleaning, a sterilized curved needle is pushed through the thick cartilage fold. The jewelry is then inserted into the pierced region.