This vintage Eclipse 77 Saw Set came in, and I give it a bit of a go with learning how to set the teeth properly on my recently cleaned up Gents Saw.
It has a broad setting range for 4 TPI to 12 TPI on a continuous dial, but it definitely gives your hand a workout when you have lots to do!
The kerf afterwards is notable for sure, though it doesn't technically make the saw sharper, but helps clear out the waste that the teeth are cutting from the stock.
Overall, a very important tool in the kit for maintaining your saws.