---
product_id: 267765409
title: "PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack)"
brand: "prime-line"
price: "6603 Ft"
currency: HUF
in_stock: true
reviews_count: 5
category: "Prime Line"
url: https://www.desertcart.hu/products/267765409-prime-line-defender-security-u-9909-chain-door-guard-door
store_origin: HU
region: Hungary
---

# 3-5/16” solid brass lock body 6-inch, 8-link welded steel chain Easy install with included fasteners PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack)

**Brand:** prime-line
**Price:** 6603 Ft
**Availability:** ✅ In Stock

## Summary

> ⛓️ Lock in peace of mind with style and strength!

## Quick Answers

- **What is this?** PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack) by prime-line
- **How much does it cost?** 6603 Ft with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hu](https://www.desertcart.hu/products/267765409-prime-line-defender-security-u-9909-chain-door-guard-door)

## Best For

- prime-line enthusiasts

## Why This Product

- Trusted prime-line brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Universal Fit:** Compact 3-5/16” size fits a variety of door types and can be mounted over or beside door casings.
- • **Effortless Setup:** Quick, hassle-free installation with all necessary fasteners included—security upgrades in minutes.
- • **Child-Safe Design:** Install out of reach to prevent children from opening the door, adding peace of mind for families.
- • **Controlled Access:** Allows door to open slightly for safe viewing and ventilation without compromising security.
- • **Secure with Style:** Solid extruded brass and satin chrome finish for a sleek, durable look that complements any modern door.

## Overview

The PRIME-LINE Defender U 9909 Chain Door Guard combines robust solid brass construction with a satin chrome finish and a 6-inch, 8-link welded steel chain to provide reliable door security. Designed for easy installation with included fasteners, it allows safe door ventilation and viewing while preventing unauthorized entry. Its child-safe mounting option and universal fit make it an essential upgrade for home or office security.

## Description

This U 9909 Chain Door Guard Lock is a security locking device for doors, allowing a door to be slightly opened to allow safe viewing and ventilation. This door lock can also be installed out of reach of children so they cannot open the door by themselves, providing additional child-safe door security. Installation is quick and easy with fasteners included, providing added security for your home or office doors. This door guard is constructed of extruded brass with a satin chrome finish and a 6 inch, 8-link welded steel chain. The 3-5/16 inch chain guard can be used on a variety of door types and can be placed over or beside door casing. It features a 6 inch long, 8-link welded steel chain and all installation fasteners necessary for complete install.

Review: Easy install and looks very nice.
Review: Buena calidad y resistencia del material de la cadena.

## Features

- SECURITY LOCKING DEVICE – This U 9909 Chain Door Guard is a security locking device for doors, allowing a door to be slightly opened to allow safe viewing and ventilation.
- CHILD-SAFE SECURITY DEVICE – This door chain lock can also be installed out of reach of children so they cannot open the door by themselves, providing additional child-safe door security.
- EASY INSTALLATION - Installation is quick and easy – additional security for your home or office doors are within reach! Installation fasteners are included.
- DURABLE CONSTRUCTION – This chain door guard is constructed of extruded brass with a dull chrome finish and a 6”, 8-link welded steel chain. It’s strong and durable and sure to last.
- PRODUCT INFO – The 3-5/16” U 9909 Chain Door Guard can be used on a variety of door types and can be placed over or beside door casing. It features a 6-inch long, 8-link welded steel chain and all installation fasteners necessary for complete install..For all dimensional information please refer to the line art and compare to your needs before purchasing

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004AHR9S0 |
| ASIN  | B004AHR9S0 |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #23,999 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #5 in Door Chains |
| Color | Satin Chrome |
| Customer Reviews | 4.5 4.5 out of 5 stars (3,828) |
| Customer reviews | 4.5 4.5 out of 5 stars (3,828) |
| Date First Available | 3 April 2014 |
| Date First Available  | 3 April 2014 |
| Finish | Chrome |
| Included components | lock, keeper and fasteners |
| Item Package Quantity | 1 |
| Item Weight | 132 g |
| Item model number | U 9909 |
| Item model number  | U 9909 |
| Manufacturer | Prime-Line Products (Home Improvement) |
| Manufacturer  | Prime-Line Products (Home Improvement) |
| Material | Steel |
| Part number | U 9909 |
| Product Dimensions | 8.41 x 1.59 x 5.08 cm; 131.54 g |
| Product Dimensions  | 8.41 x 1.59 x 5.08 cm; 131.54 g |
| Size | 3-15/16 in. |
| Style | Standard |

## Images

![PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack) - Image 1](https://m.media-amazon.com/images/I/514XZaSrPfL.jpg)
![PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack) - Image 2](https://m.media-amazon.com/images/I/51FuGlLGGhL.jpg)
![PRIME-LINE Defender Security U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack) - Image 3](https://m.media-amazon.com/images/I/61dVarMBStL.jpg)

## Questions & Answers

**Q: Do this work on doors with molding?**
A: Yes they do.  I used them on 4 different doors, all with a different kind of molding, and they work absolutely great!!  I'm very pleased with them.

**Q: Would the chain break if someone tried to forcefully enter through the door? (not talking about the screws just the chain)**
A: Yes.  My medium-sized dog tried to get through the door I 'secured' with this, and the anchor at the end of the chain  popped right off.

**Q: Has anyone installed this on a solid wood door? I’m afraid it might split the wood?**
A: Pre-drill the holes.  The quality of the chain was very weak though.

**Q: Instructions for installing door lock?**
A: Easy to install, you just need a screwdriver and it will not protect against strong pressure on the door!  Only if the children do not come out

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by C***J on 24 November 2025*

Easy install and looks very nice.

### ⭐⭐⭐⭐⭐ Review
*by C***N on 16 April 2025*

Buena calidad y resistencia del material de la cadena.

### ⭐⭐⭐ Review
*by D***S on 20 March 2024*

Os parafusos são maiores do que os buracos , tive que comprar parafusos novos

## Frequently Bought Together

- Prime-Line U 9909 Chain Door Guard – Door Chain Lock for Door and Home Security, 3-5/16”, Solid Brass Construction and a Dull Chrome Finish (Single Pack)
- EverPlus Home Security Door Lock with 8 Screws, Childproof Door Reinforcement Lock with 3 Inch Stop Withstand 800 lbs for Inward Swinging Door,Upgrade Night Lock to Defend Your Home (Silver)

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**Shop now:** [https://www.desertcart.hu/products/267765409-prime-line-defender-security-u-9909-chain-door-guard-door](https://www.desertcart.hu/products/267765409-prime-line-defender-security-u-9909-chain-door-guard-door)

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*Product available on Desertcart Hungary*
*Store origin: HU*
*Last updated: 2026-02-27*