The Frog is the lightest, most compact mechanical ascending system available, used widely in Europe and by expedition cavers world-wide. The Frog is a sit-stand system that does everything fairly well, but excels at technical rope work. The Frog is also great anytime you have multiple drops with horizontal passages in between because of its simplicity and size.
The GGG Frog (without ascenders) includes everything you need for climbing rope: GGG Frog Chest Harness, GGG Adjustable Frog Single Foot Loop, MR short oval, adjustable safety strap, dynamic rope double cow's tails with two lon-locking carabiners, and GGG Caver Seat Harness with MR half-moon screwlink. You must have the ascenders or purchase them separately to have a complete system.