Not released yet as far as i know, but have seen them in testing so hopefully available very soon.
But the Nanobyte SCT tyres are good on astro, only available in A compound, spikes/pins are much bigger than the buggy tyres so they are more like a minispike size.
bit vicious on front of a 2WD truck, even with trimming although i've just been told that schuey grey hard SCT foams help this.. i run very used 2 rows on each side dremelled Koarse Kings on the front with dBoots untrimmed on rear with yellow fastrax inserts, works a treat.
A1 Hobbies have plenty of dBoots Nanobyte SCT tyres and inserts in