I hate questions like this, as they are long-shots. It suggests to me a bit of impatience, but I do understand how exciting your 1st breedings can be so let's cover what you need to consider:

Firstly any male under 500g that's producing sperm may be capable of breeding, but extra precautions must be taken. Breeding can take allot out of a young male, he can lose significant weight & must be pulled from breeding if he does. Also there is no guarantee that a little male will go. At 580g I had a male who was producing sperm, he was willing to be with the girls, but the poor boy locked all the wrong parts... he got it right next season. So my point is, you can try, but the odds are against you.

If you are interested in what general size most every male I have will in fact lock up with a girl- that size is around 800+g. It's a nice size, & the male will easily service 2-4 females. You should still monitor them at this size, but I've not had any trouble at this size.