What's the name of a four-letter T-shirt?

It's called obey, a street brand in America.

Obey is short for Obey Giant. Most of the design inspiration of this brand comes from rock and hip-hop musicians. Clothes are mainly light street clothes, including sweaters, T-shirts and wide-body pants.

Its brand features are mostly graffiti and illustrations, with a strong Soviet-style capitalist propaganda color, a combination of photography and painting, and a unique yellow-red color scheme.