I inadvertently sent a partial review so I am continuing now. The construction is far superior to ones i have seen of comparable price. Once assembled I am impressed of the stability of the tower. I can't see it ever tipping over even with the six rambunctious cats we have. The sizes of them vary greatly from 6 to 20 pounds each. I can foresee many years of use of the unit. Thank you for offering such quality products. L. Smith Oshawa ON.