PROS - very inexpensive ($14 CDN for 100 tablets) - each 67mg tablet treats 5.5 gallons of water - can be used to sterilize surfaces, wash vegetables, sterilize containers etc - zero odor, taste - tablets are a compacted powder form, not a gooey paste tablet like PRISTINE tablets - only water treatment tablet approved by WHO (World Health Organization) and DOD. CONS - one tablet treats 5.5 gallons........so if you have a 1 liter bottle you need to make a solution (in small nalgene bottle) and dose your canteen with a few drops. - 30 min treatment time - however this can be sped up by increasing the dosage. LINK tablet size compared to a dime. setup for bulk solution for hiking. 1 tablet dissolved in water. these will ideal for the earthquake kit, disasters etc where water quality is bad. Also good for truck camping...1 to 2 tablets will treat the 20 liter nato water can , providing clean drinking water, hand washing water etc.