It is a H. aurora. Ring tentacles are different than H. malu. Aurora often for sale as zebra anemones by Petco. The don't get very big.
Found an older post of yours (cut/ paste below)
is this info still good??
From anemone FAQ
Heteractis aurora (Beaded, or Sand anemone)
Difficulty: More difficult.
Maximum size: 1 foot in diameter, though large sizes rarely seen in trade.
Recommended Minimum Tank Size: Small-medium (minimum 10 gallons).
Placement in Tank: In the sand only.
Light: Metal halide lighting.
Current: Low - moderate.
Natural clown fish symbionts:
A. akindynos
A. allardi
A. bicinctus
A. chrysogaster
A. chrysopterus
A. clarkii
Split history in captivity: None.
Additional info: Unique “knobby” tentacles make this anemone easy to identify.
Frequently available in a sandy brown color, but occasionally seen in bright purple or
other bright colors. Like other sand anemones, prefers to bury its base deep in the sand,
with its oral disk lying flat on the surface of the sand.
Fed it again today, nassarius snails tried to rob it,, anemone must have a good sting as they quit after a few tries...