This grower is sure of this plant identification.
a small variety of rupestris in 5cm pot
Crassula genus (Jade plant). These are perennial evergreen, succulent shrubs and sub-shrubs. There are about 300 species in this genus. The flowers are produced in terminal panicles or clusters.
They are frost hardy to frost tender, min 5-7C. They will prefer full sun while others like partial shade. Grow them in very well drained soil with a little water in the winter. Most are easy to grow.