In the 1980s professional percussionists from the two major New York City orchestras listened to almost 40 different head types. Four 1-1/8 models, OR39 (brown), OR42 (tan), OR45 (white) and OR48 (black) were selected as having the most frequent application to the major orchestral keyboard parts of the late 19th and 20th centuries. They are still found in the mallet bags of many professional percussionists.
https://malletech.com/mallet-series/new-orchestral-series-xylo/