When you trigger spawn maturity for an SNS Neuron, a new neuron will immediately be spawned. It's important to note that the newly spawned neuron will not have the SNS token, only maturity.
Maturity is an attribute of a neuron; it is not a tradable asset. Neurons receive voting rewards in the form of maturity. Once maturity is burned to form the relevant SNS token, maturity modulation helps to determine how many newly minted SNS tokens are given.
When you are ready to Spawn a neuron and disburse, click on the disburse button and you will be prompted to select what percentage of the maturity you would like to spawn from the neuron.
Select the destination wallet address and the amount of maturity to Spawn.
You will be asked to confirm the amount of maturity being disbursed.
Spawned neurons will have a dissolve delay of 7 days and will be initially set to dissolving. After 7 days, the new neuron will be unlocked and ready to be disbursed (see image below).
The amount of the relevant SNS token that will be available and minted from the neuron's maturity will be up to +/- 5% based on the recent market price of relevant SNS token. The maturity modulation process was created to improve the tax situation for neuron holders, giving them a better idea of how much newly minted SNS tokens will result from maturity and making it easier to compound maturity with the least manual effort. For more information, check out the Internet Computer Wiki and the DFINITY Forum.