These Alcyon hinged handcuffs are a particularly robust design, finished in black oxide which is particularly suited to covert law enforcement.  The design is unique to Alcyon like their special universal joint.  A really innovative specification respected by law enforcement agencies around the World. 

Type of Link	Hinge
Key	Standard
Construction	Riveted
Mechanism	Double lock treated
Toothed	Double
Weight	360 grs.
Length	215 mm.
Minimum opening	50 mm.
Maximum inside perimeter	165 mm.
Minimum inside perimeter	200 mm.
Locking Position	20
Construction	Steel K-60
Rockwell B Hardness	HRB-92
Thickness folded	20 mm.
Complies with salt spray test and resistances tests