The present invention relates to novel improvements to an apparatus for uniformly decomposing compressed tablets into a uniform size powder form. More particularly, the present invention is directed to improvements to the rotor cap of the apparatus allowing the rotor cap to be easily removed from the apparatus without the need for removal tools thereby allowing easy conversion from right hand operation to left hand operation and vice versa. Such improves also allow for disassembly and cleaning. Additional improvements including providing for a coding tab configured to represent predefined information such as ownership and previous use.