Description
Silicone hollow stopper with outer diameter 21 mm is a flexible laboratory sealing accessory intended for reliable closure of flasks, bottles and other glassware openings. Produced from silicone, the stopper combines elasticity with chemical resistance, supporting use across sample storage, reaction setups and general laboratory handling where an inert seal is required. The 21 mm outer diameter is sized for a secure fit on matching vessel necks, helping limit contamination and evaporation during routine work. Each piece has a net weight of 0,0037 kg. Supplied in practical packs of 10 pieces from manufacturer Deutsch & Neumann, these hollow silicone stoppers are well suited to chemistry, biology, pharmaceutical and quality-control environments. The hollow construction aids insertion and removal while retaining shape under typical laboratory conditions, and the silicone material permits repeated use and cleaning. They form part of the standard range of silicone and rubber stoppers employed for everyday labware sealing tasks in research and industrial laboratories.
This article is part of Ground-joint glass stoppers, in Stoppers, caps & closures.
Key features
- Pack size: 10 pc(s)
- Material: Silicone
- Outer diameter: 21 mm
- Type: Hollow stopper
- Country of origin: Germany
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Questions about hollow-stopper Silikon, outer Ø 21 mm
What is this article?
hollow-stopper Silikon, outer Ø 21 mm is the article on this page. Luminix Health distributes Deutsch & Neumann for laboratory use. It sits in Ground-joint glass stoppers, inside Stoppers, caps & closures, in Labware.
A ground-glass stopper matches a ground neck of a stated joint size. A 14/23 stopper does not seal a 29/32 neck. The stopper is part of the flask's seal, and a chip on the grind is a leak.
A closure is the part that decides whether a bottle stays shut and whether the contents attack the seal. A ground-glass stopper matches a ground neck. A screw cap needs the right thread and a liner that survives the liquid. Rubber and silicone stoppers push into a mouth. The liner, not the colour of the cap, is the chemical choice. The vessels they close are indexed under ISO laboratory glassware.
Which category should I open next?
The category is Stoppers, caps & closures. The sub-category is Ground-joint glass stoppers. The catalogue is Labware.
Shelves beside this one are Screw caps & closures, Rubber & silicone stoppers, Lids & seals and Closures (other).
What should I check before I order?
When this page shows a safety data sheet, use that manufacturer file. Hazard text does not belong in the sales description. For a pack size, a grade or a certificate that is not on the page, send a quote request or contact the team.
How does ordering and shipping work?
Luminix Health distributes this article from the heart of Europe. Articles in stock ship within 2–5 business days. Standard delivery is free from €250 excl. VAT. Cold-chain goods and dangerous goods under ADR are never included in that free delivery. The terms are in the Shipping Policy. The full brand index is on shop by brand. Who we are is on about us.
Which other categories should I open?
The seven catalogues are Labware, Lab chemicals, Lab instruments, Lab consumables, Chromatography equipment, Lab safety equipment and Life Science & Microbiology.