A front group is formed of a negative first lens as a meniscus lens which is convex at the object side and a negative second lens, and a rear group is formed of a biconvex positive third lens, an aperture stop, a negative fourth lens and a biconvex positive fifth lens. -% based on the total weight of the casing. Such an interlock arrangement includes a non-threaded stud engaging a hole. In a particular embodiment, the tension member includes a plurality of individual load carrying ropes encased within a common layer of coating. For example, the data may be an acknowledgement for an acknowledged mode DL transmission.