There are 4 main types of Handcuffs for Sale in the UK, the more traditional rigid, semi-rigid and chain link style metal handcuffs and then the fourth type, plasticuffs.
When it comes to preference most police or security officers prefer the rigid type of handcuffs, though these are harder to find on sale in the UK as the original manufacturer and patent holder of this design (Hiatts) went out of business whilst still in possession of the license and no one was quite sure if they could legally manufacture rigid cuffs. Rigid handcuffs have long been the most popular as they offer the maximum amount of control over a detainee with the minimum amount of force (and risk). Users however do have to be trained on this type of cuff to avoid legal repercussions if the detainee suffers an injury whilst cuffed. Rigid cuffs are now available for sale in the UK from the manufacturer THC.
During the void left by Hiats liquidation ASP (most famous for it's batons) released their semi rigid, or hinged cuffs. These were a half way house between rigid and chain link handcuffs offering some degree of lateral control if gripped in the centre. Whilst these were much more effective than chain link they were still not any were near as good or popular as the rigid handcuffs. ASP do these hinged cuff style in steel, available in black, blue, yellow and pink and a light weight rust resistant powdered aluminium.
Chain link handcuffs are the most widely available cuffs on sale and have been produced by a wide range of manufacturers from the tactical, to the novelty. The leading manufacturer is probably ASP again for the tactical market, and probably Ann-Summers for the non tactical market. Chain link handcuffs offer the least control over a suspect and do not allow for "stacking" whilst cuffing.
Plasticuffs are designed for mass detention, offering a cheap, disposable solution to restraining detainees as they have to be cut off to be released. Plasticuffs are a quick and easy option and due to the tight nature of the binding on the wrists offer excellent control over anyone bound in the them. Plasticuffs are mainly sold by ASP, Monadnock and Deenside.