The Micro Engineering 42-106 is a 3-point die-cast metal track gauge for HOn3 Code 55 — used when handlaying track or building turnouts. Three pickup points contact each rail at NMRA-correct gauge so you can slide the gauge along your work as you spike each tie, guaranteeing accurate gauge through the entire run.Why 3-point: Two-point gauges only set the gauge at one cross-section — a 3-point gauge spans a short length of track, so it catches narrow/wide spots as well as the actual gauge. Indispensable for clean, derail-free handlaid trackwork.About Micro Engineering: Micro Engineering is the gold standard for prototypical fine-scale track among serious modellers — known for scale-size moulded ties / tie plates / spike heads, irregular tie spacing that matches real-railroad practice, and fine-scale code-correct rail. Scale: HOn3 (HO 1:87 on 10.5mm narrow gauge) Code: Code 55 Material: Die-cast metal Type: 3-point track gauge Distributor SKU: 255-42106 In stock at Oakville Model Trains Depot.