Features: Lightweight spandex back provides shade and is UPF rated to 50+. Formfitting vest cut for fast and light athletic endeavors. Three-layer construction in chest panel cools the core when wet. versized armholes allow full range of motion Wicking outer layer reflects heat and facilitates evaporation Absorbent middle layer stores water for evaporation Mesh lining keeps dog dry and comfortable Sizing: XS:17-22 in S:22-27 in M:27-32 in L:32-36 in XL:36-42 in