I got these bands to do some muscle training excersizes at home using resistance bands. These resistance training bands seems to be made of high quality latex. They came in a small carry bag and individually wrapped in plastic sleeves. There are 3 different colour bands of varying resistance labelled with their level of resistance which are very light, medium and very heavy. The level of difficulty increases with an increase in the thickness of the bands. These bands are light weight, strong and portable and hard wearing. I stretched them quite a lot and they didn't loose their shape, teared or break. The bands came with a pamphlet with 7 different excersize showing in pictures. On the other side of the pamphlet there were some more instructions and questions/answers.
I would recommend to do these resistance training 3 times a day to allow recovery between training and do them with normal cardiovascular training for achieving maximum health goals and building muscles.