Buffers and chain coupler
Buffers and chain couplers ( also known as "buffers and screw" , "screw" , and "English" couplers ) are the de facto UIC standard railway stock coupling used in the EU and UK , and on some surviving colonial railways , such as in South America and India . 
<triplet> Buffers and chain coupler <subj> railway stock coupling <obj> subclass of