holdbacks

/HH OW1 L D B AE0 K S/
noun
  1. 1

    Restraint (act or result of holding back, device that restrains)

  2. 2

    The projection or loop, on the thill of a vehicle, to which a strap of the harness is attached, to hold back a carriage when going downhill, or in backing.

  3. 3

    The strap or part of the harness so used.

Source: https://en.wiktionary.org/wiki/holdback, https://en.wiktionary.org/wiki/holdbacks