The PVS-CB-12 three star black Buna-N static safe (10¹¹-10¹² ohms/sq) non-marring straight probe (working temp. -5° to 250° F) is .5" in diameter. It is for use on all our vacuum tools with the exception of the Roto-Pic® and PV-500. Product Categories: Vacuum Tools - Pen-Vac Size (Tip Width x Tip Height): .5" (12.5mm) dia. x .5" (12.5mm) dia. Body Width x Body Height: n/a x n/a Tip Angle: Straight OAL: 1"(25.39) Weight: 0.35 Ounces Max per Carton: 1 Country of Origin: USA