Think Tank Photo Glass LimoNarrow light weight backpack specifically for long lenses up to an 600mm f 4 or regular DSLR gear KEY FEATURES Accommodates large glass or a medium large sized kit of standard zoom lenses Specially designed collars for long lenses Specially designed zippers hold their position to avoid accidental opening of the main compartment ADDITIONAL FEATURES Expand the bag's capacity by adding up to three Modular Pouches for lenses, camera bodies, water bottles,