This book covers the history of virtually every commercial builder of Lotus Sevens and replicas. It focuses not only on their commercial histories though - it also highlights the technology that each builder (and, in some cases, parts suppliers) has brought to the forum. It is well written, easy to read, and well illustrated with tons of photographs. If you're building or buying a 7 or replica, read this book first. I'm building one, have been researching the build on and off for over 30 years, and I still learned a great deal from Dennis' book.