Abstract: A U-strap mounts a nut between the legs of the strap for rotation perpendicular to the longitudinal axis of the strap. The nut is provided with a threaded bore which threadably receives an adjustment sleeve. The adjustment sleeve is also threaded internally reversely to its external threads and threadably receives a stud connected to or constituting a first member to be placed under tension with respect to a second member coupled to or constituting the strap. The turnbuckle is particularly useful in mounting standard wire or rod rigging on a sailboat or sailing yacht.