This is a combo set of four men's casual shirts by Calvin Klein, stacked one on top of the other.

Key Features:

 * Brand: Calvin Klein, as indicated by the "Calvin Klein" tag and the embroidered "ck" logo on the chest pocket of each shirt.

 * Material: The shirts are made of what appears to be a soft, breathable cotton fabric, as suggested by the texture and drape.

 * Style: The shirts are a classic, casual button-down style with full sleeves. They have a standard shirt collar and a single chest pocket on the left side.

 * Fit: Based on the overall look, they appear to be a slim or regular fit.

 * Color Combo: The set includes a versatile range of solid, plain colors:

   * Top shirt: White

   * Second shirt: Maroon or deep red

   * Third shirt: Light blue or sky blue

   * Bottom shirt: Light yellow or lemon yellow