---
product_id: 514503071
title: "Watts USG-B-M2 3/8\" Under Sink Guardian Thermostatic Mixing Valve (0204141)"
brand: "watts"
price: "$258.36"
currency: USD
in_stock: true
url: https://www.desertcart.us/products/514503071-watts-usg-b-m2-3-8-under-sink-guardian-thermostatic
store_origin: US
region: United States of America
---

# Tamper-resistant locking nut for secure settings Built-in check valves prevent water crossflow Lead-free brass for ultimate durability Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve (0204141)

**Brand:** watts
**Price:** $258.36
**Availability:** ✅ In Stock

## Summary

> 🔥 Secure your perfect water temp—no compromises, no surprises! 🔒

## Quick Answers

- **What is this?** Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve (0204141) by watts
- **How much does it cost?** $258.36 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/514503071-watts-usg-b-m2-3-8-under-sink-guardian-thermostatic)

## Best For

- watts enthusiasts

## Why This Product

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

## Key Features

- • **Integrated Check Valves:** Ensures flawless separation of hot and cold water lines for consistent comfort
- • **Certified ASSE Compliance:** Meets rigorous safety standards for peace of mind
- • **Premium Lead-Free Brass Body:** Engineered for long-lasting corrosion resistance and safety
- • **Tamper-Resistant Locking Nut:** Keeps your temperature settings locked in—no accidental changes
- • **Versatile Three-Port Cap Included:** Ready for complex plumbing setups without extra hassle

## Overview

The Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve features a durable lead-free brass body, tamper-resistant locking nut, and built-in check valves to prevent water crossflow. Certified to ASSE standards, it ensures safe, reliable temperature control for under-sink plumbing applications, packaged compactly at just 349g.

## Description

WattsUSG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve (0204141)

## Features

- Lead Free Brass body construction
- Includes tamper resistant locking nut to prevent accidental misadjustments, Built in check valves prevent migration of hot water to cold and cold water to hot water piping, Provided with cap for three port application

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | Watts |
| Part Number | USG-B-M2 3/8" |
| Package Dimensions | 9.7 x 8.99 x 6.4 cm; 349 g |
| Item model number | USG-B-M2 |
| Material | Bronze |
| Item Package Quantity | 1 |
| Certification | ASSE |
| Batteries included? | No |
| Batteries Required? | No |
| Item Weight | 349 g |

## Product Details

- **Material:** Bronze
- **Brand:** Watts
- **Exterior finish:** Bronze
- **Inlet connection size:** 0.38 inches
- **Inlet connection type:** Compression
- **Outlet connection type:** Compression
- **Number of ports:** 4
- **Outlet connection size:** 0.38 inches
- **Specification met:** ASSE
- **Valve type:** Thermostatic Mixing Valve

## Images

![Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve (0204141) - Image 1](https://m.media-amazon.com/images/I/61e07W5s+eL.jpg)

## Questions & Answers

**Q: is this product lead free**
A: Yes

**Q: Does this valve has total flow shut-off if cold supply fails? similar to the cash acme thermostatic valves.**
A: Yes it is an ASSE 1070 valve- to get that rating a valve has to provide that protection.

**Q: is the kohler  k 99799 na  the same mixing valve as watts usg b m2 3/8 mixing valve/?**
A: Looking at them they seem the same. Hot and cold supply with mixing of the two to have a controlled warm water for your hot faucet and maintain a cold 
Pass through for the cold faucet.

**Q: Can you asjust the temperature?**
A: Yes.

## Frequently Bought Together

- Watts USG-B-M2 3/8" Under Sink Guardian Thermostatic Mixing Valve (0204141)
- Faucet Supply Lines 3/8" to 3/8" Female Compression Thread 1 Pair, ARCORA 9“ Faucet Hose Connects Kitchen Bathroom Sink to Water Supply

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-05-18*