Bought one as a sample. The experiment worked, but the patient died. These trucks have flat sideframes, not appropriate sculpted ones like Kadee and others. The truck is rigid, despite the spring which are only cosmetic. Worst, the bolster hole is enormous, and way out of the range allowed by NMRA Recommended Practice RP23, which calls for 0.089 dia. These trucks have a hole that's 0.168 dia., nearly twice as large. The #2 screws I use fall straight through, head and all. If you're replacing trucks on a Bachmann product that uses their proprietary, non-standard truck attachment, these might work, but they'd still be ugly. It's unfortunate that the burden of identifying parts and products that meet NMRA Standards and Recommended Practices is greater than a single retailer can afford. So too that the NMRA doesn't have an accessible list of compliant products.