4189936 - Technic, Axle and Pin Connector Angled #4 - 135 degrees. Instructions for the main build missing but available at the Lego website or on the Digital Building App. Instructions for the alternate build are present.
LEGO TECHNIC: Rescue Helicopter (8068)
LEGO Technic 42057 Ultralight Helicopter Instruction Manuals Booklets Only
LEGO Technic 2-in-1: Ultralight Helicopter & Aircraft (42057), Manual, Box
Lego Building Instructions Technic 8046 Helicopter, Helicopter
Lego Technic Set 852 Airplane Helicopter Technic with OBA Instructions RARE HTF
