Zeta Phi Beta Sorority Paraphernalia Women's Satin Sleep Bonnet. Blue Silky Satin Sleep Bonnet / Sleeping Cap with Comfortable Fit Stretch Elastic Band Around the Hairline. Breathable and Gentle on Hair. Bonnet Features ZPB Greek Letter Detailing. White Lined Interior. Bonnet Measures 12" When Laid Flat. Elastic Band to Edge Measures 4.75". 95% Polyester Satin, 5% Spandex.