SB limping

I play at about 25/15 but I very rarely limp except on the SB. My figures from this position are 37/6. I get a little confused at which hands are profitable with different numbers of limpers. Is A7os much good against one limper? Am I getting drawing odds to play semi-connected unsuited trash with 3 limpers?etc. I know a lot of this is player dependent but some general ideas would help. Thanks.

If this has been discussed before just point me to the correct info.

What do you know about the limper?

I'm sure it's a leak but I like to do it too. I run at about 35/9 in my SB.