Block® R (Half A Wig) For Replaceable Tops, Options for Block® R include Half Wig, Bangs, 7x5, 9x6, and 13x6. Many styles are currently in development. ISEE Block® Wig includes Block R & B replacements, R for Replaceable Top, B For Bottom Base, Block R + Block B = A Whole Wig, Supporting Versatile Styles.