Gucci monogram heels, size :6 +B, tan and blue/green

Gucci monogram heels, blue green with beige and GG, the box says size 6+B I'm not sure exactly what that means. Very good condition, worn a handful of times. there is minimal wear, at the bottom of the sole on the green/blue part there's a tiny chip. As shown in pictures. Heel size about 5 inches . The heals come with extra heel replacements. Also comes with the original box