| Unit | Sizes | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| US & Canada | 6 | 6.5 | 7 | 7.5 | 8 | 8.5 | 9 | 9.5 | 10 | 10.5 | 11 | 11.5 | 12 | 13 | 14 | 15 | 16 |
| UK | 5.5 | 6 | 6.5 | 7 | 7.5 | 8 | 8.5 | 9 | 9.5 | 10 | 10.5 | 11 | 11.5 | 12.5 | 13.5 | 14.5 | 15.5 |
| Europe | 39 | 39 | 40 | 40-41 | 41 | 41-42 | 42 | 42-43 | 43 | 43-44 | 44 | 44-45 | 45 | 46 | 47 | 48 | 49 |
| Inches | 9.3 | 9.5 | 9.6 | 9.8 | 9.9 | 10.1 | 10.3 | 10.4 | 10.6 | 10.8 | 10.9 | 11.1 | 11.3 | 11.6 | 11.9 | 12.2 | 12.5 |
| Centimeters | 23.5 | 24.1 | 24.4 | 24.8 | 25.4 | 25.7 | 26 | 26.7 | 27 | 27.3 | 27.9 | 28.3 | 28.6 | 29.4 | 30.2 | 31 | 31.8 |
The EXTREK C923 men's trail running shoe is built as a breathable, lightweight daily trainer for rugged terrain. A non-waterproof engineered-mesh upper maximizes airflow and quick-dry comfort, while targeted overlays add durability in high-wear zones. Underfoot, an EVA midsole delivers responsive cushioning to reduce impact on hardpack and gravel, and a removable insole enhances step-in comfort while helping manage moisture and odor. Traction comes from a grippy rubber XS Trek outsole with multi-directional lugs for confident control on loose gravel, roots, and wet rock. A locked-in heel and a roomier toe box promote stable footing on climbs and descents without pinching. Part of the EXTREK trail line, the C923 is designed for runners who want breathable comfort and dependable grip without a waterproof membrane—ideal for dry to mixed conditions, fast efforts, and everyday trail mileage.

