HO-SCALE SINGLE RANDOM STONE PORTAL - Realistic detail. High density white hydrocal casting. HO-Scale (1:87) Single Random Ptone portal is easy to color, and meets NMRA specifications. One piece. Outside measurements: 5-11/16"W x 5-1/8"H. Inside measurements: 2-13/16"W x 3-3/4"H. Assemble with Woodland Scenics Foam Tack Glue (WD1444), Lightweight Hydrocal (WD1201), or Scenic Glue (WD0190). Color with liquid pigments (WD1215-WD1223). Instructions included.