Loco buffers is a varied subject. For instance class 37s have had large diameter round Oleos, oval head, rectangular and elliptical headed buffers over the years. Class 60s have had elliptical and ovals. Class 90s have had two types of retractable buffers chopped round and full circle and a mix of oval and elliptical. In the case of the class 60 and 90s some locos have had one of each oval and elliptical at one end at one point.