Right now, we are using the quickset 6mm, 23" tubing and only use his backside for pump sites. I put his cgms in his arms. For those of you who have really then children, where else do you try? He is very thin - lean muscular build. His backside is not looking the greatest - Endo always says it's fine but I would like to give it a break. My question is - if you use the leg and/or arm - where do you put it so it's comfortable and do you order longer tubing??? Stomach is out, he is just way to skinny there - No fat at all.