MTDE Garma chest harness. Solid, versatile and efficient chest harness well suited to sustained SRT (when used with an appropriate sit harness, of course!). Very adjustable, with three hang points for climbing gear, bolt / survey kits, or just cowstails. Can be tensioned or slackened off very easily using a single, well placed buckle. Not cheap - but really efficient and useful, especially if you are aid climbing, bolting as part of exploration, or just do lots of rigging.
This chest harness has also been used as part of a cave diving harness - but it was never designed with that in mind...