"For best results only order crystals from the manufacturer "
Yes, the problem is that MS-Apple requires customers to buy not only the crystals, but also the subspace contanment field generator, a neutrino shield, and a unit whose only apparent function is to flash an eerie blue glow and hum ominously..... This is what they call 'DiLithium crystal replacement kit'... The cost of this 'kit' is ~15 times more than the crystals themselves.