--- product_id: 57230268 title: "United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers | Good to Seal Bottles, Tubes and Many Other Containers - Black Lab Plug | #00 to #7 Assorted Sizes | 1LB of Stoppers" brand: "united scientific" price: "€ 34.22" currency: EUR in_stock: true reviews_count: 13 category: "United Scientific" url: https://www.desertcart.hr/products/57230268-united-scientific-rstpk2-premium-laboratory-black-rubber-stoppers-good-to store_origin: HR region: Croatia --- # Tapered Design Reusable & Sustainable Temp Range: -25 to 70°C United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers | Good to Seal Bottles, Tubes and Many Other Containers - Black Lab Plug | #00 to #7 Assorted Sizes | 1LB of Stoppers **Brand:** united scientific **Price:** € 34.22 **Availability:** ✅ In Stock ## Summary > 🔧 Seal the Deal with Style! ## Quick Answers - **What is this?** United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers | Good to Seal Bottles, Tubes and Many Other Containers - Black Lab Plug | #00 to #7 Assorted Sizes | 1LB of Stoppers by united scientific - **How much does it cost?** € 34.22 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/57230268-united-scientific-rstpk2-premium-laboratory-black-rubber-stoppers-good-to) ## Best For - united scientific enthusiasts ## Why This Product - Trusted united scientific brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Seamless Sealing:** Experience effortless sealing with our smooth tapered design. - • **Durable & Reliable:** Crafted from premium rubber, these stoppers resist deformation. - • **Eco-Friendly Choice:** Join the sustainable movement with reusable natural rubber stoppers. - • **Temperature Resilience:** Withstand extreme temperatures from -25 to 70°C without a hitch. - • **Versatile Applications:** Perfect for labs and industries—seal test tubes, flasks, and more! ## Overview The United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers are designed for versatility and durability, featuring a tapered design for easy use. Made from high-quality natural rubber, these stoppers are reusable and eco-friendly, suitable for sealing a variety of laboratory containers. With a temperature range of -25 to 70°C, they are perfect for both industrial and educational settings. ## Description One-pound bag of solid black rubber stoppers, sizes 00 to 7. Made of natural rubber that stays pliable over a long period of time. Ideal for use with non-aggressive or concentrated solutions. Low sulfur content. Will withstand temperatures from –25°C to 70°C (–13°F to 158°F). Autoclavable. Review: Good For Many Uses - They are rubber corks meant for science, but we used them for something different. In building a portable solar generator (DIY Goal Zero Yeti 400) I was trying to find a way to secure the bettery inside of the plastic ammo box used for the generator housing to attach everything to and needed a way to protect the battery from the screws protruding in from attaching things to the outside of the box. I screwed the charge controller and inverter on opposite sides of the box and used these rubber pieces to screw onto the back of the pointy end of the screw inside the box. This worked great not only to protect the battery from the screws, but they also happened to be the exact right size to where the battery slips in the box, snuggly right between the rubber bumpers with no modification using a 396wh battery. Sometimes you need to think outside the box and this worked perfectly for what I needed them for! Review: Excellent - Perfect for what I was using them for especially with the different sizes they had ## Features - Tapered Design - Smooth and tapered sides make these stoppers easy to plug and pull. All United Scientific rubber stoppers are reusable, and promote a sustainable laboratory or classroom environment. - Natural Rubber - Made from premium natural rubber, not easy to deform, elastic and great for sealing. Manufactured according to laboratory standards - Extensive Use - Rubber stopper Ideal for laboratory and industrial use, can be used to seal test tubes, flasks, etc. Available in a wide range of sizes. - Low sulfur content. Withstand temperatures from –25 to 70°C (–13 to 158°F). They do contain latex. - Size: #00 to #7 Assorted sizes, 1LB stoppers. ## Technical Specifications | Specification | Value | |---------------|-------| | Customer Reviews | 4.3 out of 5 stars 303 Reviews | ## Images ![United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers | Good to Seal Bottles, Tubes and Many Other Containers - Black Lab Plug | #00 to #7 Assorted Sizes | 1LB of Stoppers - Image 1](https://m.media-amazon.com/images/I/51rfnQ0GD3L.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good For Many Uses *by P***T on May 16, 2020* They are rubber corks meant for science, but we used them for something different. In building a portable solar generator (DIY Goal Zero Yeti 400) I was trying to find a way to secure the bettery inside of the plastic ammo box used for the generator housing to attach everything to and needed a way to protect the battery from the screws protruding in from attaching things to the outside of the box. I screwed the charge controller and inverter on opposite sides of the box and used these rubber pieces to screw onto the back of the pointy end of the screw inside the box. This worked great not only to protect the battery from the screws, but they also happened to be the exact right size to where the battery slips in the box, snuggly right between the rubber bumpers with no modification using a 396wh battery. Sometimes you need to think outside the box and this worked perfectly for what I needed them for! ### ⭐⭐⭐⭐⭐ Excellent *by C***S on April 30, 2026* Perfect for what I was using them for especially with the different sizes they had ### ⭐⭐⭐⭐ Works great with filter flask *by R***S on August 16, 2018* Works great. I used it for an object lesson experiment with a flask and filter. I gave it 4 stars only because I only needed one stopper but couldn’t find it in smaller quantities. ## Frequently Bought Together - United Scientific RSTPK2 Premium Laboratory Black Rubber Stoppers | Good to Seal Bottles, Tubes and Many Other Containers - Black Lab Plug | #00 to #7 Assorted Sizes | 1LB of Stoppers - 10 Pieces Stainless Steel Lab Spatula Micro Sampling Scoop Double Ended Mixing Spoon Laboratory Measuring Spoon for Powders Gel Cap Filler - Smalltongue Mica Powder for Epoxy Resin, 36 Colors, 0.35 oz(10g) Bottles Mica Glitter, Pigment for Lip Gloss, Soap Making, Bath Bomb, Art Crafts, Resin Dye, Nails --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/57230268-united-scientific-rstpk2-premium-laboratory-black-rubber-stoppers-good-to](https://www.desertcart.hr/products/57230268-united-scientific-rstpk2-premium-laboratory-black-rubber-stoppers-good-to) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-06-20*