Harrows Dimplex Nylon Shafts. A patented industry first, featuring Turbulators for increased air flow and optimum flight. Length: 34mm; (does not include thread – 5mm) Thread: 2baHarrows Dimplex Nylon Shafts with Machined Rings. A patented industry first, featuring Turbulators for increased air flow and optimum flight. Length: 45mm; (does not include thread – 5mm) Thread: 2ba Harrows Dimplex Shafts – Dart Stems – with Rings – White