It was an eventuality he had prepared for; but again, with his rough-and-ready tools, the chances of success were far less than with the kind of instruments he was accustomed to having at his disposal. Certainly, his magnetic picklock was not an impressive-looking piece of equipment, having been jury-rigged with electrical tape and epoxy. He had removed the core of the solenoid and replaced it with a steel rod. At the other end of the rod, he had attached a thin rectangle of steel, which he had cut from a tin of butter cookies using heavy-duty scissors. The electronic part ー a random noise generator ー was a simple circuit of transistors he had extracted from a Radio Shack cell phone. Once he connected a pair of AA batteries to the apparatus, a quickly oscillating magnetic field was created: it was designed to pulse at the sensors until they were activated.
Robert Ludlum, The Janson Directive, 2002.
1) crude, unpolished, or hastily prepared, but sufficient for the purpose
2) (of a person) without formality or refinement; rudely vigorous [CED]
Rough or crude but effective for a purpose or use. [AHD4]