Towing with a convert a ball

I just picked up a 32 foot fiver with a goose neck convert ball adaptor attached. Which my truck had a built in Goose neck ball in the bed.. my question is I've never towed with this type of adaptor, is it safe? I have seen a lot of fivers with this type of adaptor and just wanted to see if I can get more insight. the most I'm going to tow is about a few hundred miles at a time 3 to four times a year..