Sent in a scathing review of an office chair to Amazon. The bloody thing cannot be assembled by following the instructions as two of the four screws attaching the arms to the seat back cannot be aligned. The only method that worked was to loosely attach the arms to the seat back, then also loosely attach the two rear screws on the arms to the seat base. Now the remaining two screws that go into the foremost part of the seat base can be wrestled into position, best done with three hands but I only had two available. Then all the screws get tightened and the plastic caps are fitted to hide the screws.
Next I hammered and levered and bashed the special easy-roll wheels off the old seat to fit to the new chair. These wheels are single 3-inch rubber ones rather than the dual two-inch plastic piece-of-crap castors than come will all such chairs. The chair rolls a lot easier and also gains an extra inch in height.