We study the centralising algebra of a natural action of the hyperoctahedral group (i.e., a finite Weyl group of typeBr) on ther-th tensor power of a2n-dimensional space. The centralising algebra of this is shown to have a product rule similar to Schur's product rule in typeA. We deform this action to an action of the Hecke algebra of typeBand study the associated centralising algebra of typeBand its dual. We introduce and studyq-permutation modules for the algebra.