YCL-857II, YCL-847II. Specifications. Key, Bb, A. Fingering System, Oehler, 27 keys, 5 rings, Oehler, 27 keys, 5 rings. Barrel Length, 54mm, 56mm, 54mm, ...
https://nl.yamaha.com/nl/products/musical_instruments/winds/clarinets/ycl-857ii_847ii/specs.html