The black 2 prong linear, 180 degree, Orbit atom can be used to represent carbon in triple bonded structures; the triple bonding can be implied or if used with an "X" peg can show the 3 bonds.
Indigo Instruments has held inventory of genuine Cochranes of Oxford atoms & bonds for over 30 years (scroll down to see "Skeletal (Orbit/Minit)". These parts are 100% compatible with every set & kit we've ever sold. Why buy from others where support could end the day after?
You can use these Genuine Cochranes of Oxford Orbit Molecular Model Parts to replace missing pieces or augment any of the Orbit Molecular Model Sets & Molecular Model Kits supplied by Indigo Instruments.