The 412EPI R/H Aft Equipment Shelf mounts in the upper right avionics bay and provides added provisions for up to 100 pounds of additional avionics equipment. Note: Approved for S/N 37002 and Sub or w/ 412EPI upgrade kit STC. The 412EP L/H Aft Equipment Shelf mounts in the upper left avionics bay and provides added provisions for up to 130 pounds of additional avionics equipment. The (505-029-001) Avionics Shelf installs in the truss area of the helicopter and provides space for installation of additional avionics. Avionics Shelf is installed to mounting provisions on the aircraft truss. Max capacity of the shelf is 25 lb / 11.3 kg This shelf is required for installation of: Traffic Advisory System (Garmin GTS-800) Radar Altimeter (Garmin GRA-55) Genesys HeliSAS Autopilot The (505-035-001) Expanded Avionics Shelf provides a larger avionics shelf with a maximum shelf capacity of 100 lbs (45 kg) and replaces Avionics Shelf (part number 505-029-001) when additional mounting area or shelf capacity is required. The Boattail Shelf installs into the boattail area of the helicopter and gives the installer an extra space in the aircraft for installation of a multiple number of items. Maximum shelf weight not to exceed 66 lbs.