Under Armour Hg Rush Compression Ss-Red Compression T-Shirt. Under Armour Hg Rush Compression Ss-Red compression t-shirt. Men's short-sleeved compression t-shirt with innovative Rush technology. Rush technology uses mineral-enriched fibers to recycle the energy used and return it to you. Mesh panels provide extreme breathability. The technology used ensures maximum comfort, the modified cut with raglan sleeves provides extreme mobility. Low-profile collar. Material: 84% Polyester, 16% Elastane