What is the fine-grained topic of the following text: This kit includes a 1-Liter AQUA-POUCH™ (Designed & Developed by Survival Resources - see Water Containers, product 17201), 10 Chlorine Dioxide Water Purification Tablets (which are effective even against Cysts such as Cryptosporidium - Iodine & Chlorine are not), 5 Pre-Filters (to prefilter water before purification), a Pre-Filter Support Sheath (another item made exclusively by Survival Resources), as well as directions for use. Only return the topic.
Water Purification Kit Components