Speedcuffs are a model of handcuff characterised by their rigid grip between the two ratchet cuffs. Their rigid design and the inclusion of a grip makes them effective for gaining control over a struggling prisoner, even if only one cuff has been applied. They are standard issue for most police forces within the United Kingdom. Amnesty International has criticised the handcuffs, claiming that implements made by the company have been used around the world to torture prisoners. Construction Speedcuffs consist of two conventional ratchet handcuffs connected by a rigid metal bar, which is enclosed in a plastic grip secured with bolts. Removal of the grip offers no advantage to escape, as it is only present to facilitate the comfortable manipulation of the cuffs by the arresting officer. Weighing 390 g (13.75 oz) and with a maximum dilation of 23.2 cm (9.13 inches), the speedcuffs are slightly larger than the chain-linked and hinged handcuffs previously manufactured by Hiatts, and accommodate a greater range of wrist sizes. They feature Hiatt's 'back loading' feature, which allows the ratchet to be pulled backwards for a few "clicks" through the lock casing to set the cuffs in the ideal position for quick application. The locks accept a standard handcuff key, and have a double locking facility which is activated through a small pin on the back of the cuff. The double locking facility must be depressed with a pointed object, such as the protrusion found on the top of the handcuff key; double locking prevents accidentally or knowingly tightening the cuff once it has been locked, helping to prevent paralysis or other injury. Application The mechanism of speedcuff application is the same as other modern "swing through" handcuffs. By pressing the pivoted arm of the cuff against the wrist, the arm can be made to swing around the wrist and engage with the lock. The officer may then tighten the cuff to an appropriate position before applying the other cuff, engaging the double locking system to prevent the handcuffs tightening further. Owing to the rigid design, speedcuffs can be applied in one of four different positions, which also apply to hinged handcuffs but not chain-linked. In British police training, these positions are termed 'front stack', 'rear stack', 'palm to palm', and 'back to back'. Many forces teach two positions to their officers, but some teach all four. The 'stacked' positions are those where, once applied