Q1: what assures cards dont fall out?
A1:This card case has a hard rubber interior to good for fitting the cards securely within the lining,comes with a card pin, which allows you to take the card more conveniently
Q2: Is this waterproof?
A2:Theres a rubber seal ring to keep water out.
Q3: What the size of this case?
A3:It is 142.5mm x 82.8mm x 31mm (5.6" x 3.3" x 1.2") and 157 g.