Jermesa Studio - 15 FREE sci-fi Alpha/Height panels Sci-Fi brush and alpha sample set for Quixel and Substance painter, 15 brushes and height/alpha maps, all 2048x2048. The full version for this set
22 Free Sci-Fi height/alphas
SciFi Alpha Map Pack vol 1 - Blender Market
350 Hard surface sci-fi Alpha/Height VOL 2 — polycount
20 Free Hardsurface Height/Alphas sur Behance
3D ALPHAS for MECH/SCIFI DESIGNS TUTORIAL EXPLANATION FREE Gumroad link in description - YouTube