Optimize your laboratory's chromatography sampling with these premium open-top screw caps. Engineered for reliable autosampler performance, excellent sealing, and superior chemical resistance, these caps are the perfect choice for professional HPLC and GC analysis.

📌 PREMIUM FEATURES & PRACTICAL APPLICATIONS:

• Autosampler Optimized (Open-Top): Features a wide 8.5mm center hole, allowing autosampler needles to penetrate smoothly and accurately without bending.

• Ultimate Chemical Resistance: The white PTFE layer directly faces the sample, providing a highly inert barrier against harsh chemicals, acids, and aggressive solvents.

• Excellent Resealability: The red silicone backing provides outstanding elasticity. It automatically and effectively reseals the puncture hole immediately after needle extraction, strictly preventing sample evaporation.

⚙️ DETAILED TECHNICAL SPECIFICATIONS:

• Product Type: Screw cap with pre-assembled septa

• Closure/Neck Finish: Standard 13-425 (13mm screw thread)

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

• Septa Construction: White PTFE / Red Silicone

• Septa Dimensions: 13mm x 1.5mm

• Compatibility: Exclusively designed to fit standard 13-425 (4mL) screw top vials.

💡 AVAILABLE BULK PACKAGING OPTIONS: We offer flexible wholesale packaging to suit both small and large-scale lab requirements. Please carefully select your required quantity from the variation menu:

• 300 pcs (Ideal for small labs or short-term testing)

• 500 pcs (Standard choice for regular daily use)

• 1000 pcs (Best value for high-throughput laboratories)

⚠️ IMPORTANT PURCHASING NOTES:

• Accessories Not Included: You are purchasing the Caps and Septa only. Vials are strictly sold separately unless explicitly listed as a bundle.

• Strict Safety Restriction: Approved strictly for laboratory research and analytical use only. Do not use for any medical injection, clinical, or hypodermic purposes under any circumstances.