These Alcyon rigid handcuffs are exclusively made available to the Handcuffs Shop.  They are normally only sold to the Basque Police in Northern Spain, the region in which Alcyon handcuffs are manufactured.  As you can see from the picture the big difference between the ordinary 5050 model is the rigid bar between the two 'cuffs.  A very solid pair of handcuffs offering the law enforcement officer a greater degree of control as with all rigid handcuffs.