The product is a lot of four mystery and crime novels by Eric Ambler from the 1950s to the 1970s. These novels fall under the genre of mystery, with a focus on crime as the topic. The novels are likely to feature thrilling plots and engaging storytelling that keeps readers on the edge of their seats, making them a captivating read for fans of mystery and suspense genres. With Eric Ambler's reputation for espionage thrillers, these novels are sure to provide an exciting and suspenseful reading experience for readers interested in vintage crime fiction.