Spillways Protocol is an upgraded & gas efficient fork of Tornado Cash that takes a fixed value as deposit (0.1 / 1 / 2 / 5 ETH), then mixes it with the deposits of the other users in order to guarantee the privacy of your transactions making them nearly untraceable.
Spillways is a fully decentralized protocol for private transactions on Ethereum which is proposing a mixer to allow the users to keep anonymity for their transactions. Spillways is a fork from Tornado Cash with an improved ZK-Proofs protocol.