This rock style base is called "Dual" because two rocks are anchored together to make a single unit. These rock bases are ideal for the Coyote, Red Fox, Gray Fox and Bobcat mounts that have the front raised high as though they are standing on a stump or in this case, a rock. The Urethane rocks are created from a semi-flexible urethane, reinforced with wood making them strong yet very light. The Original rocks are created from the original material that is strong, resists chipping and is stable. Both have the same shape and texture.
View: How To Measure Rocks