The newest incarnation of the extremely useful BRASS OFFSETS have softer edges and a double transverse taper (like the bow of a ship). Excellent in pin scars and flares, where the double taper resists rotating or rocking. Each face is slightly concave which gives more "bite" to the placement. Add 'em to your free climbing rack for a boost in strength in the small sizes (compared to other aluminum nuts). Add 'em to your aid climbing rack to slot into Lost Arrow piton scars - faster and rock friendly! 1-3 sets absolutely necessary on most El Cap routes. Made in U.K.