I replaced a kitchen sink faucet on a old sink with a more modern faucet. This faucet did not come with a separate hand sprayer like many of the old ones did back in the day. The replacement faucet did not come with a plug for the extra hole and the original was breaking and rusting.

This left my sink with an extra hole where water could drip down into the storage under the sink. This sink hole cover/plug is made for holes no smaller than 29.5mm in diameter. If your hole is larger than 42mm in diameter, this may be too small, unless you scale it up. This 42mm is the start of a 2mm rounded trench where you can fill with a sealant. (hot glue gun, custom o-ring, 3D printed o-ring, etc). I used a TPU filament and just filled it in with my 3D pen.

The length of the bolt is 40mm, so it will fit fairly thick sinks.

Not supports are needed, but you may want to use a brim around, at least, the bolt to ensure good adhesion.