Style #18650, 18700.
All attachments use #8 x 1 1/4" wood screws. Be sure to pilot all screw holes.
All wood is solid hardwood 3/4" thick (although the front and rear wood cleats could be 1- 1 1/4" thick to make screwing boards to the bottom edge of the cleat easier). Maple or Oak is a good choice. (cleats may be Poplar wood) No plywood. Avoid Pine and "Whitewood" as they are too soft to resist screw tear out. Obviously, no particle board. When certain of wood placement, glue and screw is always best.
This glider is intended to be attached to the bottom edge of the chairs sides. Sides may not be solid wood and in order to prevent splitting of the sides material, piloting of screwholes is necessary. Screws should not be heavy in thickness but should penetrate deeply. The two attachment flat plates have a large variety of holes to faciitate different choices of attachment. These anchor plates can be reversed to use with the "flat" in an upper or lower position to suit the chairs height. The lower position is most common. Serrated anti-loosening nuts and bolts are used for safety. If removed, the bolt must first be loosened in order to remove the nut.
One option for installation when the sides are not in line with the anchor flat plates is to widen the plate(s) using wood by securely attaching a 1" thick board to the plate. Then, screw the 1" board to chair bottom edge sides.
Some additional install information included with #18219-26 gliders.