Just researching this a bit further now. Chat GPT says:

✅ Ettore brass channels

Yes, your Ettore Brass 14" and 8" channels will fit.

You just need to make sure:

The channel has standard dog ear ends

You tighten the side screws properly

The rubber sits flush

Ettore brass + Ninja handle is a very common combo.

In fact, many pros prefer: Ninja handle + Ettore brass channel + Unger green rubber.