Alpinestars SMX-6 V3 Boots. Advanced microfiber upper construction for lightweight high performance protection against abrasion, and superb levels of flexibility. Front flex and back flexion zones are constructed with textile over-injected with a soft TPU for enhanced impact abrasion resistance, while also promoting a natural forwards and backwards movement. Unique ankle brace protection system provides a bio-mechanical support and protection between the lateral top calf, shin, and ankle for superior ankle articulation. Lace-Lock System is constructed from an advanced polymer resin for a guaranteed quick, precise, and secure closure. TPU shifter zone for superior protection on the lower medial side. Strategically positioned, race-derived TPU shin plate protector delivers superior impact and abrasion resistance.