Intrusion Systems | ISN‑GMX‑P3S4 Spacer (4 mm) ISN‑GMX‑P3S4 Spacer (4 mm) 4 mm (0.2 in.) thick. Ordering Information ISN‑GMX‑P3S4 Spacer (4 mm) 4 mm (0.2 in.) thick. ISN-GMX-P3S4 www.boschsecurity.com