Any Open Source OTP Hardware Token?

I am looking for something like this: https://www.vasco.com/products/two-factor-authenticators/hardware/one-button/digipass-go-6.html

that doesn't require paying high fees for the authentication server.

Google provides an open source authenticator server, I am looking for the client part implemented in hardware that works with it. https://github.com/google/google-authenticator

I know about Yubico but their tokens don't come with a led display, you need to plug them to a USB port which it's an issue if you want to log in from your phone.