Most controlled technology is dual-use. Bearings, machine tools, thermal cameras, navigation modules, microcontrollers and radio-frequency amplifiers all have unremarkable commercial markets and all appear in weapons recovered from conflict zones.
The consequence for detection is that the item itself rarely gives the game away. Field investigators working back from recovered components rely on manufacturer part numbers and batch markings, tracing them through distributors to the last documented lawful sale, and the divergence between that sale and the recovery site is where the diversion happened.