กระเป๋า Billingham รุ่น 35 Rucksack-Black Canvas / Tan Leather

Which is bigger? The '25 Rucksack' or the '35 Rucksack'?
The 25 Rucksack is larger.

I don't like the padded insert being narrower at the top. What can I do?
The Hadley Pro insert will fit in there instead. Its a tight - but it does fit.

Does this bag need re-proofing to keep it waterproof?
No. The fabric is made of 3 layers - the middle layer is butyl rubber. Water cannot pass through this butyl rubber layer. As long as you don't get a hole in the fabric or expose it to harsh chemicals (for example in a washing machine) the fabric should remain waterproof for many years. There is no need to apply re-proofing.

External Dimensions
W310mm (12¼") x D200mm (7⅞") x H380mm (15")

Internal Dimensions
Inside padded insert: W230mm (9") x D75mm (3") x H240mm (9½")
In main compartment with padded insert removed: W260mm (10¼") x D180mm (7⅛") x H380mm (15")

Capacity
Inside padded insert: 5.6 litres (0.20 feet³)
In main compartment with padded insert removed: 7 litres (0.25 feet³)
In front pocket: Additional 1.8 litres (0.06 feet³) in front pocket.

Weight
1.17kg (2.58lbs)

External Front Pocket internal dimensions
W200mm (7⅞") x D60mm (2⅜") x H170mm (6¾")

Shoulder Strap Measurements 
Length: can be adjusted between 480mm (18⅞") to 980mm (38⅝") approx.