Keyless2Go Replacement for Keyless Entry Remote Car Key Vehicles That Use 3 Button OHT692427AA

What size battery

What if I have 1 original with keyfob and 1 without? Or can you just use the 1 with the keyfob twice?

Will it lock & unlock the doors after successfully programming and the engine starts

Will this for sure work with an 05 jeep grand cherokee?