How much does it weigh? How much space does it take up in a bag? Would it be good for backpackers?

Weight: 15 oz. (426 grams)Canister (diameter x height): 2.75 in x 3.9 in (7 cm x 10 cm)Pump Length: 5.5 in (14 cm)Tube Length/ Pre-Filter Length: 35.8 in/ 3.1 in (91 cm/ 8 cm)GREAT FOR BACKPACKING:*Quick, Easy & Convenient- no chemicals, hold time, double pumping required!*First Need Pump: reliable · easy grip, palm molded handle · double action pump - fast flow with less work · field serviceable.*Gravity Assist Kit- "hands free" purification without pumping, even with a clogged canister!*First Need "Structured MatrixT" Sealed Canister: no brushing, scraping, or contact with contaminants · integral safety cover · backwashable.*"Direct ConnectT"- purifier attaches snugly to many popular trail and bike bottles.*And More: long non-kink intake hose · self cleaning pre-filter with adjustable float · water resistant nylon tote bag.*Award Winning: 2002 "Gear of the Year Award" Outside magazine 2002 Buyer's Guide · 2000 Consumers Choice Award - OutdoorReview.com