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.
Daith piercing. From Wikipedia, the free encyclopedia. A Daith piercing is an ear piercing that passes through the ear's innermost cartilage fold, the crus of the helix. In most areas this piercing is pronounced day-th although the proper pronunciation is doth (rhymes with moth). The piercing is located in a 'awkward place' to pierce due to it being in a curvy place, and being usually pierced with a straight hollow needle.