GRAYL MAKE A GOOD WATER FILTER BOTTLE THAT DOES A GREAT JOB OF WATER PURIFICATION IN THE FIELD.AT THE TIME OF THIS VIDEO I COULD FIND NO VIDEO SHOWING A COOK SET BUILT AROUND THE GRAYL WATER BOTTLE SO I MADE ONE.THIS VIDEO IN PART IS A GRAYL PRODUCT REVIEW AND IN PART IS MY TAKE ON HOW A COOK SYSTEM WOULD WORK