The 700-TFL-9001 is an HC-49U/US base insulator designed for crystal oscillator packages. This component features precision-molded dimensions with specific pin hole specifications: pins A and C have a diameter of 0.40 mm, while pin B has a diameter of 0.80 ±0.03 mm. The insulator body measures 4.45 ±0.05 mm in length, 0.20 ±0.05 mm in thickness, and 4.88 ±0.10 mm in width, with an overall height of 10.80 ±0.10 mm. This base insulator is commonly used in crystal oscillator assemblies where precise mechanical alignment and electrical isolation are required, providing reliable support and positioning for HC-49U/US package configurations.