As far as we can ascertain, this is a unique product, indeed our expert advisers tell us that a product using this combination, was never made in the 'darby' era. Comprising a neck collar joined with 20 cm of chain to a pair of handcuffs (916) which are in turn linked to a pair of leg irons (918) with a further 60 cm of chain.  Prisoners have the burden of an extra 1.8 kilograms (4 pounds) of heavy metal.  Not a recipe for high speed escape!  Please see individual sizes of the leg and handcuffs in their separate descriptions.