This t-shirt bra features demi, underwire cups for smooth yet supportive fit under clothes. The J-hook in back connects the straps together to create a racerback.Details: Seamless T-shirt bra has contour, underwire cups with light padding for a smooth, supported bust Center - low, plunge panel is sturdy sheer lace Wide-set, satin elastic straps adjust at top back, down to O-rings where they attach to high back apexes Seamless sides and back are lined with microfiber and have covered elastic along the top and bottom for custom fit Coated metal J-hook on upper back O-ring brings straps together to make an instant racerback Center back has coated hook-and-eye closure. See Fitter's Comments for hook counts Calvin Klein style# QF9005