Photo: Courtesy of Sir

Joanna Baum, owner of the two fabulously stylish Sir boutiques in Brooklyn, is branching out from clothes design: She has started making single-strand silver- and gold-plated chain necklaces that are simple and understated enough to fit anyone's style. The suede straps come in an array of fun color options like scarlet, lilac, periwinkle, pink, and black, and can be layered over a simple tank or tee. Baum named the necklace "Marcella" for the smart and sexy girl the Beach Boys sing about in their 1972 track. We think we just found our summer trinket.

$40 to $60 at Sir, 129 Bedford Ave., nr. N. 10th St.; 718-384-0700.