Callahan Mimi Dress in Black. - size L (also in S, XS, M, XL) Callahan Mimi Dress in Black. - size L (also in S, XS, M, XL) 95% cotton 5% elastane. Made in China. Hand wash. Unlined. Pull-on styling. Crossover halterneck styling with open back. Ribbed knit fabric with front keyhole and side seam slits. CAHN-WD58. 32218. Los Angeles based brand Callahan is known for their comfy sweaters and perfect boyfriend fits. Their line is elevated by unique textures, materials, and techniques that give each piece versatility and wearability. Designed for cool girls everywhere, Callahan is inspired by effortlessly easy style.