An ingenious design that was fabricated to eliminate notal tone disruptions and allows for proper notal tone frequencies to flow smoothly inside of the slide crook and/or body tube and over the waterkey dispensary.
- It features a brass plug that sits in the waterkey cup and has a brass stem that fills the inside section of the waterkey dispensary. This results in lever waterkey assemblies responding acoustically similar to push-button waterkey assemblies.
- The waterkey plug, when effectively seated into the waterkey cup, acts as a harmonic balancer weight while also allowing for the plug's stem to fill the empty chamber space inside of the waterkey dispensary.
- The purpose of making the waterkey plug out of brass is to avoid causing adverse distortions and suppression of the instrument's natural resonance—which can occur from having a full rubber or full cork material.
- What allows for an effective seal of the plug onto the waterkey dispensary is the use of an O-ring, constructed of a neoprene rubber/cork blend material, that is inlaid flush onto the beveled lower base of the plug’s stem—to prevent any sort of air leakage from coming out of the slide crook and/or body tubing.
The results of effectively “plugging” the waterkey dispensary are:
- Having an even flow and distribution of notal tones throughout the general section of tubing; and
- Having a true, balanced response and resistance to the player when sounding the instrument.
Available Waterkey Plug Size Options
- Size Option #1 — Besson (Sovereign/Prestige), Jupiter XO, Kanstul, UMI (King Silver Flair, Benge Leonore 90B, C.G. Conn Vintage One, etc.), Yamaha (short waterkey pip)
- Size Option #2 — Bach Stradivarius/Omega (main tuning slide ONLY), Eastman (Euphoniums), Willson (Euphoniums), Yamaha (tall waterkey pip)
- Size Option #3 — Adams, B&S, CarolBrass, Eclipse, F.E. Olds (standard [not side-lever action] waterkey assemblies ONLY), Schilke (all available series), S.E. Shires (Trumpets, etc.), VanLaar
- Size Option #4 — Bach Stradivarius/Omega (3rd and 4th [Piccolo] valve slide ONLY), S.E. Shires ("Q Series" Euphoniums, etc.)
*** Please Note: The waterkey assembly may need to be adjusted by a technician to properly fit the Harmonic Waterkey Plug(s) if OEM waterkey parts were made and installed with a faulty alignment. ***
Feel free to reach out with questions or comments to see if your waterkey is compatible with the Bájoc Harmonic Waterkey Plugs!
Manufactured in the USA!

