Description
Rubber stopper with a top diameter of 26,5 mm, bottom diameter of 21 mm and height of 27,5 mm provides a tapered natural-rubber seal for medium-neck laboratory glassware and bottles. Made from red natural rubber, the stopper combines flexibility with a firm friction fit, helping to close vessels securely during sample storage, mixing or short-term holding of reagents. The conical geometry simplifies insertion into openings within the stated diameter range, while the greater height of 27,5 mm gives a stable seating depth. This pack of 10 pieces from manufacturer Labbox is suited to laboratories that need a defined mid-size rubber stopper without overstocking. Net weight is 0,173 kg per pack. Applications include sealing Erlenmeyer flasks, reagent bottles and other containers where a soft rubber interface is preferred over hard plastic or cork. Clear dimensional specification supports repeatable selection across teaching, analytical and production environments that rely on standardised laboratory stoppers.
This article is part of Rubber & silicone stoppers, in Stoppers, caps & closures.
Key features
Recently viewed
You may also like
Browse related categories
Category
Sub-category
Catalogue
Brand
Questions about Rubber stopper, solid, Øtop. 26,5 mm, Øbottom 21 mm, h 27,5 mm, 10 pcs
What is this article?
Rubber stopper, solid, Øtop. 26,5 mm, Øbottom 21 mm, h 27,5 mm, 10 pcs is the article on this page. Luminix Health distributes Labbox for laboratory use. It sits in Rubber & silicone stoppers, inside Stoppers, caps & closures, in Labware.
A rubber or silicone stopper is pushed into a mouth. The size number corresponds to a top and bottom diameter. Silicone survives higher temperatures and more autoclave cycles. Natural rubber is attacked by oils and by some solvents.
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 Rubber & silicone stoppers. The catalogue is Labware.
Shelves beside this one are Screw caps & closures, Ground-joint glass 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.

