Compatibility: 1/87 HO Model Train Test Track Module is designed to work with roller test stands. Compatible with 1/87 HO scale model trains from most brands. Function: Test track bearing (roller trolleys) allows testing of model trains on tracks or layout setups. Diagnostic Module: Single unit treadmill track for testing or repairing 1:87 HO scale trains. Helps analyze idling performance and movement to identify potential issues. Note: Train not included. Expandable: Multiple units can be connected for expanded diagnostic configurations. Durable base provides structural stability for use in exhibitions or repair work. Included: 1 Diagnostic Treadmill Unit. Specification: Material: Metal and plastic Size: 5.12 cm / 2.02 inches Package Includes: 1 x 1/87 HO Model Train Test Track Module Note: Slight variations of 1–2 cm (0.39–0.79 inches) may occur due to manual measurement.