The product doesn't come with any instructions so you're left to your own devices to try and figure out how to assemble the buckle. After doing this you'll quickly realise that the buckle is very weak and doesn't support your body weight whatsoever... however you need to sort of double loop it over the fix point and through the buckle gap again and then tape it up (which is easy since you'll have loads of rope left). Once this has been done it is completely secure. I weigh 14 stone and it supports me fine. Who knows, I may have assembled it wrong but since there's no instructions how am I to know?! Overall a great product once you've figured out how to secure it properly.