Venturi Tool
The Venturi Tool has two purposes.
1) The tapered end, when inserted into the trumpet leadpipe and lightly tapped, will slightly bevel the square edge of the leadpipe/beginning of the venturi. This will make the trumpet play more open.
2) The square/flat end, when inserted into the trumpet leadpipe and lightly tapped, will "square up" the edge of the leadpipe/beginning of the venturi. This will make the trumpet play less open.
The diameter of the tool is such that it works for most trumpets. Custom sizes are available if needed (either from your measurements or from mine via a shop visit).
