9.0mm round x 3.5mm tall - Cork should fit either water key but please check size.

trumpets, cornets, euphoniums, tubas, sousaphones

 Should Fit the following:

AD-TR1
T-100N
T-100NS
T-100S
T-110S

YAH-100S
YAH-201
YAH-201S
YAH-202
YAH-202S
YAH-203
YAH-203S
YAH-601ST
YAH-601T
YAH-602
YAH-602S
YAH-803
YAH-803S
YBB-100S
YBB-103
YBB-103(2)
YBB-103S
YBB-103S(2)
YBB-104
YBB-104S
YBB-105
YBB-105M
YBB-105MS
YBB-105S
YBB-110S
YBB-201M
YBB-201MS
YBB-631
YBB-631S
YBB-632
YBB-632S
YBH-100S
YBH-201
YBH-301
YBH-301M
YBH-301MS
YBH-301S
YBH-621
YBH-621S
YCR-2310
YCR-2310(2)
YCR-2310S
YCR-2310S(2)
YCR-2330
YCR-2330(2)
YCR-2330S
YCR-2330S(2)
YCR-2610S
YCR-2610S(2)
YCR-4330G
YCR-4330GS
YCR-6330(2)
YCR-6330S(2)
YCR-6335H
YCR-6335HS
YCR-6610SDT
YCR-6610ST
YCR-6610T
YCR-8335
YCR-8335G
YCR-8335GS
YCR-8335S
YCR-8620
YCR-8620S
YCR-9435
YEB-631S
YEB-632
YEB-632S
YEP-100S
YEP-100SA
YEP-201(2)
YEP-201M
YEP-201MS
YEP-201S(2)
YEP-202M
YEP-202MS
YEP-641
YEP-641(2)
YEP-641S
YEP-641S(2)
YEP-642
YEP-642S
YEP-842S
YFH-231
YFH-2310
YFH-2310S
YFH-231S
YFH-435RT
YFH-435T
YFH-631
YFH-631G
YFH-631GS
YFH-731
YFH-8315G
YHR-167
YHR-167A
YHR-301M
YHR-301MS
YHR-302M
YHR-302MS
YHR-561
YHR-668(#20001-)
YHR-668D(#20001-)
YHR-668N(#20001-)
YHR-668ND(#20001-)
YHR-881
YHR-882
YMP-201M
YMP-201MS
YMP-202M
YMP-202MS
YMP-203M
YMP-203MS
YMP-204M
YMP-204MS
YRGB-61
YSH-301(3)
YSH-411
YSH-411S
YSL-354V(C.LAC.)
YSL-354V(G.LAC.)
YSL-354VS
YTR-01
YTR-01M
YTR-01MQ
YTR-01Q
YTR-1310
YTR-1320E
YTR-1320ES
YTR-1320S
YTR-1335
YTR-1335S
YTR-200AD
YTR-200ADM
YTR-2320
YTR-2320E
YTR-2320ES
YTR-2320S
YTR-2335
YTR-2335DX
YTR-2335M
YTR-2335S
YTR-2335SDX
YTR-2420
YTR-2435
YTR-2435S
YTR-4320E
YTR-4320EG
YTR-4320EGS
YTR-4320ES
YTR-4325S
YTR-4335G
YTR-4335GS
YTR-4335GST
YTR-4420E
YTR-4420ES
YTR-4435
YTR-4435S
YTR-5335G
YTR-5335GS
YTR-5335GSAL
YTR-6330B
YTR-6330F
YTR-6335(#401001-)
YTR-6335H(2)
YTR-6335HG(2)
YTR-6335HGS(2)
YTR-6335HS(2)
YTR-6335HSMV
YTR-6335J
YTR-6335S(#401001-)
YTR-6345G
YTR-6345GS
YTR-6345H(2)
YTR-6345HG(2)
YTR-6345HGS
YTR-6345HGS(2)
YTR-6345HS
YTR-6345HS(2)
YTR-6445H(2)
YTR-6445HG(2)
YTR-6445HGS(2)
YTR-6445HS(2)
YTR-6610
YTR-6610S
YTR-8335(#451500-)
YTR-8335G(#451500-)
YTR-8335GS(#451500-)
YTR-8335LA
YTR-8335LAS
YTR-8335RG
YTR-8335RGS
YTR-8335RSUK
YTR-8335RUK
YTR-8335S(#451500-)
YTR-8335SEU
YTR-8345(#451500-)
YTR-8345G(#451500-)
YTR-8345GS(#451500-)
YTR-8345S(#451500-)
YTR-8445(#401001-)
YTR-8445G(#401001-)
YTR-8445GS(#401001-)
YTR-8445RS
YTR-8445S(#401001-)
YTR-9335CHS
YTR-9335NYS
YTR-9445CHS
YTR-9445CHSE
YTR-9445NYS
YTR-9630
YTR-9636
YTR-9825
YTR-9835