Engineered to perform. Featuring a new Adjustable Slit Upper that will wrap and support the foot plus an updated DUOSOLE outsole for enhanced traction and flexibility, the GEL-DS Trainer 23 builds on its predecessor's powerful reputation to deliver a lightweight, speed-focused run each and every time. The FLYTEFOAM midsole stimulates bounceback while the PROPULSION TRUSSTIC technology works with your natural anatomy to propel you forward as you move through your gait cycle. Weight: 8.4. Heel Height: 20mm. Forefoot Height: 10mm.