Possible Nursing Career Change

Hi, I have an opportunity to send in my resume and cover letter to apply for a new role in Operating Room/Periop. I am somewhat nervous about the idea but highly interested too, but not 100% sure if it will be a right move.

Currently, I am working on Cardiac Surgical ward as a Grad RN and really finding out that its not what I want anymore. I thought being a Ward RN would be ideal for me, but obviously not no more. So I am hoping that maybe OR nursing would be the right role, if not I keep finding my niche until I am settled.

Therefore, I am wondering in regards to preparing a cover letter for Theatre Nursing, what I should state. Do I mention why I am interested in a great detail??

Look forward to your advice