Small Textured Rock Holds Set of 8, Blue by Swing Set Stuff Inc.. $18.95. Mounting Hardware Included. With a Bonus hat ($9.99 value). These come in red, blue, green and yellow.. These are small polyethylene molded rocks with easy grip texture surface. This is a set of 8 in three different shapes. Each rock has two mounting holes. The aprox size of each rock is 4" x 2 1/2". The colors are blue and green.