1-Hyperreflexivity and Complete Hyperreflexivity
  The subspaces and subalgebras of B(H) which are hyperreflexive with constant 1 are completely classified. It is shown that there are 1-hyperreflexive subspaces for which the complete hyperreflexivity constant is strictly greater than 1. The constants for $\bC T \otimes B(H)$ are analyzed in detail. 
Kenneth R. Davidson, Rupert H. Levene