You might want to have a metal file handy. Those metric forstner bits don’t have the teeth cut into them sometimes so you’ll have to file some teeth into them. It’s best to just order a good 30mm bit from a better retailer. You can also get those bits cheaper on ebay. The router bits look fine and you definitely can’t beat the price.
I bought those metric forstner bits on ebay from that company and they sent me the wrong size. I called them so they sent me the correct ones and told me to keep the others. I know why they told me to keep the others it’s because the metric ones were no good. You might get lucky and get some good ones either way if you find they sent you some bad ones they will replace them free of charge.
I have the chap 4 sets I bought from EDM and I also have 2 “good” sets I bought from a woodworking website.