Can anyone guide me whats the best size of rucksack for 7 - 10 days trekking ( with YHAI ) in himalayas ?? Someone suggested me with TATONKA PYROX 45 L & TRIMM RAPTOR II 45 L , since i dont want an indian product as i had purchased mount track 75 litres which tored off in my 1 st trek itself .... m totally confused with the size ... Can anyone guide me with size & gear shop in mumbai ???