Aftermarket Besson euphonium & tuba pac-man style valve guides.  Sold as 1 each.

Euphonium & Tuba 967, 968, & 2052 Prestige 22.2mm

Euphonium & Tuba 967, 968, & 2052 Prestige 4th valve & 700 3 valve tuba 22.7mm

Euphonium & Tuba 700 & 7000 international 20.7mm