This is the 3/4" Risers Bulk Pack (19) from Woodland Scenics.
FEATURES: Used with incline/decline starters to create varying grades on
Easily flexed to form curves and work on plywood or foam bases
To install, pin in place with Foam Nails and attach with foam tack
glue or low temp foam glue gun and glue sticks
Each Riser measures 3/4" x 2-1/2" x 24" (1.9cm x 6.35cm x 60.9cm)