--- product_id: 45620976 title: "4\" Extend & Lok™ for Effluent Filters" price: "£51.23" currency: GBP in_stock: true reviews_count: 11 url: https://www.desertcart.co.uk/products/45620976-4-extend-and-lok-for-effluent-filters store_origin: GB region: United Kingdom --- # Fits any 4" pipe ID perfectly Tool-free, no-glue installation Proudly made in the USA 4" Extend & Lok™ for Effluent Filters **Price:** £51.23 **Availability:** ✅ In Stock ## Summary > 🔩 Lock in reliability, unlock hassle-free plumbing! ## Quick Answers - **What is this?** 4" Extend & Lok™ for Effluent Filters - **How much does it cost?** £51.23 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/45620976-4-extend-and-lok-for-effluent-filters) ## 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 - • **Effortless Setup:** Install in minutes with no gluing or special tools required—DIY made simple - • **Universal 4" Fit:** Seamlessly centers filters or tees under risers for flawless alignment - • **Versatile Sizing:** Also available in 3" and 6" sizes to match your exact plumbing needs - • **Durability You Can Trust:** Crafted from premium materials to withstand harsh conditions and last long - • **Authorized Quality Assurance:** Buy confidently from the only authorized seller on desertcart with superior support ## Overview The 4" Extend & Lok™ for Effluent Filters is a precision-engineered plumbing fitting designed to fit any 4-inch pipe inside diameter. It centers filters or tees perfectly under risers and installs quickly without glue or tools. Made in the USA from high-quality materials, it offers durable, professional-grade performance. Available also in 3" and 6" sizes, it’s backed by authorized seller assurance and excellent customer support. ## Description Professional Grade Products Polylok products are manufactured in the USA with the BEST MATERIALS to withstand the WORST CONDITIONS. BUY AUTHORIZED! Drainage Direct is Polylok's only authorized desertcart seller. When you buy from a Polylok authorized dealer you are purchasing stringent quality checked products backed by Polylok's superior customer support. Purchase confidently when placing an order through Drainage Direct, your premiere source for Polylok products on desertcart. BUY AUTHORIZED! Drainage Direct is Polylok's only authorized desertcart seller. When you buy from a Polylok authorized dealer you are purchasing stringent quality checked products backed by Polylok's superior customer support. Purchase confidently when placing an order through Drainage Direct, your premiere source for Polylok products on desertcart. Polylok, Inc. is an international supplier of plastic injection molded products for the precast, drainage, and wastewater industries. Unlike the majority of our competitors, we design our products in-house, and manufacture in the USA. We hold more than 75 patents and produce more than 200 different products. We are constantly striving to develop new and innovative products. Drainage & Wastewater Products Visit the Store Drainage & Wastewater Products Visit the Store Review: Works well - Perfect item for repairing broken septic tank baffles. Locks tight and stays in place. Review: Worth the $$ - Considered other fittings but this one does the job without any rigging. Fast shipping, fit perfectly, and made diy job quick & easy ## Features - Fits any pipe with an inside diameter of 4" - Centers filter or tee under riser - Easy Installation - No gluing necessary - Also available for 3" pipe and 6" pipe ## Technical Specifications | Specification | Value | |---------------|-------| | Best Sellers Rank | #111,553 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #787 in Replacement Under-Sink Water Filters | | Customer Reviews | 4.5 out of 5 stars 188 Reviews | ## Images ![4" Extend & Lok™ for Effluent Filters - Image 1](https://m.media-amazon.com/images/I/41jI6HwMfgL.jpg) ## Questions & Answers **Q: Manufacturer says this can be used to extend an inlet pipe. Using this on an inlet pipe to a tank may create clogs. has any had problems?** A: Discharging my rv into the septic inlet using this piece connected to pvc. No clogs so far. **Q: Do you have the 6 inch extend & lok ?** A: Yes, https://www.amazon.com/PolyLok-Extend-Lok-Effluent-Filters/dp/B085T216N7/ref=sr_1_2?crid=1C80QAOEMN52E&keywords=Polylok+6%22+Extend+%26+Lok%E2%84%A2+for+Effluent+Filters&qid=1640266938&sprefix=polylok+6+extend+%26+lok+for+effluent+filters%2Caps%2C81&sr=8-2 **Q: What is the outter diameter of the small end (that gets twisted into the existing). It should be smaller than 4 inches so it can eventually snug up.** A: It is less than 4 inch as it did slip into the 4 inch pipe. But I've already installed so can't measure. **Q: Will this work on inlet clay pipe** A: "Fits any pipe with an inside diameter of 4" https://www.youtube.com/watch?v=iFqMv1P4h_E&feature=emb_imp_woyt Fits: Clay, Cast Iron, SCH 40 PVC / ABS, and SDR 35 PVC pipe. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works well *by A***R on April 25, 2026* Perfect item for repairing broken septic tank baffles. Locks tight and stays in place. ### ⭐⭐⭐⭐⭐ Worth the $$ *by T***S on March 30, 2025* Considered other fittings but this one does the job without any rigging. Fast shipping, fit perfectly, and made diy job quick & easy ### ⭐⭐⭐⭐⭐ easy install. tappy, tap, tap! *by N***K on August 26, 2025* saved my butt and I'm guessing a lot of cash! Septic tank is back in action. ## Frequently Bought Together - Polylok 4" Extend & Lok™ for Effluent Filters - Polylok PL-68 Effluent Filter & Housing (Baffle/Tee) - Tuf-Tite Effluent Filter EF-4 Combo --- ## 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.co.uk/products/45620976-4-extend-and-lok-for-effluent-filters](https://www.desertcart.co.uk/products/45620976-4-extend-and-lok-for-effluent-filters) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-06-29*