--- product_id: 56776560 title: "Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z" price: "€ 48.31" currency: EUR in_stock: true reviews_count: 8 url: https://www.desertcart.com.cy/products/56776560-monument-4in-100mm-x-½in-nylon-drain-testing-plug-mon1378z store_origin: CY region: Cyprus --- # Air-tight seal up to 29psi Removable top caps & rubber rings 100mm diameter fit Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z **Price:** € 48.31 **Availability:** ✅ In Stock ## Summary > 🚰 Seal the deal with confidence — test like a pro! ## Quick Answers - **What is this?** Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - **How much does it cost?** € 48.31 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.com.cy](https://www.desertcart.com.cy/products/56776560-monument-4in-100mm-x-½in-nylon-drain-testing-plug-mon1378z) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Trusted Legacy Brand:** Backed by Monument’s 75+ years of plumbing industry excellence. - • **User-Friendly Design:** Removable top caps and rubber rings for quick installation and maintenance. - • **Pressure-Resistant Seal:** Handles back pressure up to 29psi (1.97bar) for reliable testing. - • **Durable Nylon Construction:** Robust nylon plates and stem ensure long-lasting performance on the job. - • **Precision Fit for 92-107mm Pipes:** Seamlessly blocks drains with a perfect 100mm diameter range. ## Overview The Monument 4in (100mm) Nylon Drain Testing Plug is engineered for precise drain pipe blocking and air testing. Featuring a durable nylon build, removable top caps, and rubber rings, it reliably seals pipes within a 92-107mm diameter range and withstands back pressure up to 29psi (1.97bar). Ideal for professional plumbers seeking trusted, efficient drain testing solutions. ## Description Product Description Monument Tools Ltd has more than 75 years of excellence as manufacturers and distributors of equipment for the plumbing, heating and drainage industries. Monument supply a broad range of products from standard plumbers’ tools to sophisticated specialist roofing and sheet metal tools to drain-clearing equipment. Monument manufacture and distribute bestselling lines such as pipe cutters, tap reseaters, wrenches, manometers, manhole keys, drain rods and snakes. These form part of an extensive product range. 1378Z Drain Testing Plug 100mm (4in). Monument Drain Testing Plugs. Used for blocking off drain pipes. Fitted with removable top caps and rubber rings. They are capable of sealing against pressures of up to 100PSI - 7 Bar. Diameter.100mm - 4in. Manufacturer's Description Monument Drain Testing PlugsUsed for blocking off drain pipes.Fitted with removable top caps and rubber rings.They are capable of sealing against pressures of up to 100PSI - 7 Bar.Diameter.100mm - 4in. Review: Do not rust over time! - These are perfect and do not rust over time Review: Don't waste your money - These are awful, spend a couple of pound extra and buy the metal ones. We bought these to do the final drain tests on a project and they failed miserably. They just don't seal the pipes at all, so we've been out and bought the metal version and had no problems. Complete waste of money. ## Features - Used for blocking off drain pipes and for air testing - Diameter range 92-107mm. 1/2in. BSP outlet - Maximum allowable back pressure 29psi (1.97bar) - Fitted with removable top caps and rubber rings - Nylon plates - nylon stem ## Technical Specifications | Specification | Value | |---------------|-------| | Manufacturer | Monument | | Part Number | MON1378 | | Product Dimensions | 8.51 x 9.5 x 9.5 cm; 120 g | | Item model number | MON1378 | | Size | 100 mm | | Colour | Multi-coloured | | Material | Rubber | | Power Source | AC | | Item Package Quantity | 1 | | Included Components | 1378Z Drain Testing Plug 100mm (4in) | | Batteries included? | No | | Batteries Required? | No | | Item Weight | 120 g | ## Images ![Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - Image 1](https://m.media-amazon.com/images/I/61AgfbW+vXL.jpg) ![Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - Image 2](https://m.media-amazon.com/images/I/61966ZKuc0L.jpg) ![Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - Image 3](https://m.media-amazon.com/images/I/6137sKArvNL.jpg) ![Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - Image 4](https://m.media-amazon.com/images/I/21Tt9K48O-L.jpg) ## Questions & Answers **Q: I'm planning on using this as a bath plug to stop water coming up my bath. Will it work for that purpose?** A: No it is too big for a normal bath plug. It is 4 inches in diameter and generally used to plug up underground sewage type pipes. If you are using it for this purpose do not over tighten as being plastic you can pull it apart. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Do not rust over time! *by M***N on 2 August 2025* These are perfect and do not rust over time ### ⭐ Don't waste your money *by S***. on 30 January 2026* These are awful, spend a couple of pound extra and buy the metal ones. We bought these to do the final drain tests on a project and they failed miserably. They just don't seal the pipes at all, so we've been out and bought the metal version and had no problems. Complete waste of money. ### ⭐⭐⭐⭐⭐ Blocked my sewer pipe very well *by C***Z on 24 February 2022* Living in the country, we have a sceptic tank and the one 4 inch sewer pipe from our kitchen does not have any inspection chamber so when we rod the main pipe, we cannot force water back towards the kitchen. We had about 12 years worth of a fat build up in the pipe between the kitchen drain and the main sewer pipe towards the sceptic tank. This plug allowed me to block the main sewer pipe in an inspection chamber further en route which meant I could force water down the blocked pipe using drain rods. I must have pulled out a bucket full of white fat. Highly recommended. ## Frequently Bought Together - Monument 4in.100mm X ½in. Nylon Drain Testing Plug - MON1378Z - Monument 3in. 75mm X ½in. Nylon Drain Plug - MON1377W - Monument MON1376 Drain Test Plug 50mm (2in) --- ## 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.com.cy/products/56776560-monument-4in-100mm-x-½in-nylon-drain-testing-plug-mon1378z](https://www.desertcart.com.cy/products/56776560-monument-4in-100mm-x-½in-nylon-drain-testing-plug-mon1378z) --- *Product available on Desertcart Cyprus* *Store origin: CY* *Last updated: 2026-07-06*