300-1000Pcs 8-425 Black Screw Cap with PTFE/Silicone Septa 5.5mm Center Hole

These high-quality black open-top screw caps feature a dual-layer septa and are specifically designed to optimize automated sampling procedures in laboratory chromatography analysis (HPLC/GC).

📌 KEY APPLICATIONS:

• Open-Top Design: Features a wide 5.5mm center hole, allowing autosampler needles to easily and precisely penetrate the septa without resistance.

• Outstanding Chemical Resistance: The white PTFE layer directly faces the sample, providing ultimate chemical resistance and ensuring your solvent's purity remains uncompromised.

• Excellent Resealability: The red Silicone backing offers superior elasticity, automatically and effectively resealing the puncture hole immediately after needle extraction to strictly prevent sample evaporation.

⚙️ TECHNICAL SPECIFICATIONS:

• Product Type: Screw cap with pre-assembled septa.

• Cap Material: High-durability Black Polypropylene (PP).

• Center Hole Size: 5.5mm.

• Septa Construction: White PTFE / Red Silicone (Dimensions: 8x1.5mm).

• Compatibility: Fits perfectly and is designed EXCLUSIVELY for standard screw-top vials with an 8-425 (8mm) neck finish. Strictly NOT compatible with 9mm vials.

💡 AVAILABLE PACKAGING OPTIONS: Please carefully select your required bulk quantity from the variation menu:

• 300 pcs

• 500 pcs

• 1000 pcs

⚠️ IMPORTANT PURCHASING NOTES:

• Accessories Not Included: You are purchasing the Caps and Septa only. Vials are sold separately.

• Safety Restriction: For laboratory use only. Strictly do not use for any medical injection or hypodermic purposes.