Schilke D5.3 throat size

[Marzan]

Does anyone here have a throat dimension of a Schilke D5.3 trombone mouthpiece?

[Posaunus]

Per the Schilke Website, the throat is 0.281" = 7.14mm.
Not at all similar to the old Schilke 53, which had a much smaller throat

https://www.schilkemusic.com/products/m ... euphonium/

Symphony Series 5.3 Series Specifications (Rim Comparison = Schilke 53/3G)
M5.3: K (.281″) Medium Shallow Cup, provides more brilliance with a larger rim diameter than the 5.2 models.
D5.3: K (.281″) A Standard cup shape that provides a deeper bottom to the sound core.
D5.3*: K (.281″) Standard Cup with tapered throat. More open than D5.3

[Marzan]

Thanks!