The Frontier Deck Drain is a removable top drain that features a double wall base and a snap in top. When installing this drain, the tops are staggered past the joints making the joints very rigid. The removable top caps make it easy to clean the drain or replace the top caps. It is recommended that you drill and pin the base with a non-corrosive dowel at 3' intervals to stabilize against any movement of the concrete slab.