Attiny85 & Batteries

I'm just making a program using attiny85, ultrasonic sensor, and a buzzer. I'm wondering what batteries I should use. Can anyone help me with that? please...

ATtiny85 can operate at up to 10MHz with 2.7 - 5.5V, and up to 20MHz with 4.5 - 5.5V.
ATtiny85V can operate at up to 4MHz with 1.8 - 5.5V, and up to 10MHz with 2.7 - 5.5V.
So 2 or 3 AA cells can work well.
You should also consider what voltage the sensor and buzzer require.

Thank you :slight_smile:
So the sensor is 5V and the buzzer might be like 1 or 2, so is it of to connect a 9V battery?

No. Like I said, the maximum voltage for the ATtiny85/V is 5.5V.
9V will probably destroy it.

is important to know what is the grade speed any of number on MHZ??