SBR, Styrene-butadiene rubber, a synthetic rubber It´s durable, has good anti-slip properties and is flexible. It´s a dense material with good abrasion characteristics but downside is heavy weight. Normally soles with thickness >5 mm are avoided for this reason if not for a specific purpose. To manage a lower weight a midsole of EVA is often used with a bottom sole of synthetic rubber of 3-4mm thickness.
- Good abrasion
An alternative is foam rubber which is lighter and can be used for thicker outsoles but with less weight.