Heavy gauge steel construction and quality keys. You have to fold the bills very small - about two inches and it will fit about 10-15 bills before a bill almost sneaks back out, read more sure to push bills with a key of a butter knife or something, It is possible to pull out a bill with a tweezer but not easy and will destroy the bill. Suggest putting in 100's 1st then top off with 10's and 5's so fishing out will result in less amount. Make sure you have the discpline to put winnings in the box to begin with otherwise it's useless. I go to the casino about once a month and as the night progresses if I win I try to put some money aside but the gamble box makes it easy to keep money separate along with assuring that you don't make a bad decision and spend it all! It's a very durable, somewhat heavy box, but I put it in my purse 今日の現金スロットマシン was not weighed down by carrying it around. And if you read other reviews about people saying you can't put much cash into this box, well, it depends how you fold it. I fold my money where it ended up long but narrow, then in half. Try different ways, you'll figure it out, but it WILL hold a lot. This is a great little box. You have to fold the bills tight and small to get as many in the box as you can. Normally I would play my wins back, but not any longer. It works if you use it right. They say it weighs as much as a pack of cigarettes but it actually is a little more. I wear a butt pack when I go to the casinos and it fits in it 今日の現金スロットマシン />I never 今日の現金スロットマシン upset anymore from giving back all my wins.