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.
I have had chronic migraines since I was 16 years old. My triggers are mainly stress, weather changes and hormones. Before my daith piercing, I was having an average of 6-9 migraines per month. Beyond the pain, this is a problem because I am limited to 6 Relpax/month (for a low cost of $129.00 after a $100 coupon).