A Long Internal Sleeper Support Plate is used in conjunction with support spikes to secure up to four straight railway sleepers together on the internal side of planters, pathway edging and retaining walls. Features & Benefits: Heavy-duty, 2mm thick material. Suitable for all sleeper sizes. Size: 350mm Colour: Brown. This heavy-duty plate is suitable for all sleeper sizes and is designed for easy installation and a long-lasting fit for purpose landscaping solution.