Hi, You must be looking at EnduKoard boards (which is what I bought). You do need both. The Uni-trim is used horizontally as the separation between the panels, The Raili-hold is the mounting trim used vertically between the drywall and panels. Hope that helps.
Hi, You must be looking at EnduKoard boards (which is what I bought). You do need both. The Uni-trim is used horizontally as the separation between the panels, The Raili-hold is the mounting trim used vertically between the drywall and panels. Hope that helps.