My 6 month old !! strong as an ox

Hi everyone ! im either a wimp or i have one extremely strong pup. He is 6 months old and so strong can anyone advise of a very good harness for my pup. I tend to want to stay away from leather ones. So any help and advice on any other ones is most welcome.

also at the moment i am using 3-peaks and its useless

To be honest, if you've got such a puller the answer is in training, not in the harness. I use the Mekuti and find it's fantastic as a training aid especially for older confirmed pullers (we have rescues), but if you just let a dog pull in it he'll learn how to.

I like this video: http://ahimsadogtraining.com/blog/2008/10/12/silky-leash/

And these: https://www.youtube.com/watch?v=AeTBGMYZj5I&index=2&list=PL0C724F6F6A597540

https://www.youtube.com/watch?v=jJ-qvYh7TVU&index=3&list=PL0C724F6F6A597540

They're slightly different approaches but end up at the same thing. Pulling gets you nowhere, not pulling is much better and rewarding.