These inside bearing trucks were originally designed and manufactured by Hawker-Siddeley starting in 1976. The design was passed on to other manufacturers, and one of them, UTDC (which made them up until the early '90s), was acquired by Bombardier. These trucks were specifically designed for the (now) Bombardier bi-level commuter cars, and AFAIK, have not been used on any other cars. One unique feature of these trucks is their outboard disk brakes (one on each side).
Athearn makes the only Bombardier bi-level commuter cars (and hence, trucks) in N scale -