Quote Originally Posted by Dave763 View Post
Vaseline, be gentle be sure the probe is pointed toward the tail. I start sideways to get in, then rotate 90 degrees.
I would use the green or maybe the blue one hard to tell from the pic. I like a ball on the end.
I agree with Dave, also if you use a probe that is too small you can injure the snake and get a false reading. Ball on the end of the probe is always a nice choice for safety in the beginning.