Pannier bag single bag rack pack anzahl 1 material cotton coating polyurethane coated capacity 20 litres attachment quick lock 21 material properties waterproof robust ecological information pvc free safety features reflective print fastener roll closure features shoulder strap innenaufteilungen main compartment inner pockets dimensions w x h x d 42 x 2332 x 17 cm weight 840 g colour grey series ortlieb back roller