Stella SMX-6 V3 Vented Womens Boots Alpinestars Advanced microfiber upper construction with a dedicated laser perforated area for breathability offers light weight, high-performance protection Perforation padding on the entire boot for added ventilation and breathability 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 PU shifter zone for superior protection on the lower medial side Strategically positioned, race-derived TPU shin plate protector delivers superior impact and abrasion resistance