Drivers Seat off exit 5 on 195 in East Providence does it. Depending on the size of the bottle I think he is around $40-$60 per fill. Just don't go buy parts from there. Was going to buy an FMS F cam from him gave him about 150 for a deposit, he said if i find it cheaper elsewhere he'll just refund my money, wrote it on both receipts mine and his, I go to get my money back bc I found the cam cheaper he claimed that he "lost my receipt" yeah ok pal. I looked at his receipt book every single one of them were in there, not wrinkled or torn or anything, but when it came time to the page that mine was on it "dissappeared" hmmmm
Both place's charge by the pound, and NED doesn't fill bottle's but on street nite's there is a guy there with a small white trailer that sell Nitrous and other stuff, i think its 617 racing or motorsports, he has a website somewhere