Manufacturers—not universal regulations—determine the expiration dates for tree climbing harnesses. Retire your harness according to the manufacturer's specified lifespan or the results of your inspection, whichever comes first. The DMM Kinisi harnesses are the most recent on the market, and their lifespan is often directly compared to the Teufelberger Treemotion harness when reviewing expiry periods.
Unlike the Teufelberger Treemotion harness, which lists a specific discard date on its label, the DMM Kinisi harness uses the 'plus ten' method: add ten years to the manufacture date on the identity label for the expiry. To find either label, peel back the harness pack pad from the Velcro—both have labels sewn into the harness, with the DMM label being smaller.
To find the DMM Kinisi harness expiry date, use the nine-digit number found at the bottom of its label. The first two digits indicate the year of manufacture, the next three digits represent the day of that year (001–365), and the last four digits are the serial number.
To calculate the expiry, add ten years to the year and day shown in the first five digits of the label. For example, 25247 means day 247 of 2025, so it expires September 4, 2035.
Some climbers and gear checkers get highly focused on harness manufacture and expiry dates. The arb industry considers a maximum 10-year lifespan acceptable, acknowledging that actual lifespan depends on usage. For example, a harness used once a month may last approximately five years, leaving a five-year ‘shelf’ life (from factory to warehousing to purchase), which is more than adequate. Harness life is shortened significantly with use.
