Despite the thorns, this plant does have leaves and so is a succulent, not a cactus. It is hardy and can grow to be up to two metres tall.
The sap of this plant is white, hence the common name of milk tree; but is poisonous, so keep skin and eyes protected when working with this plant.
Three sizes are available, and those in the photo in the pot are small/med and medium, and contains six individual plants.
approx sizes: S 12cm, S/M 20cm, M 28cm high