• MagSert 640 shower insert on a white background
  • MagSert 640 installed in the shower arm
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MagRock Inc.

MagSert Shower

MagSert Shower

Model S-640

$69.00 USD
$69.00 USD
Sale Sold out

Measure before you order. Your shower arm needs an inside opening of at least 5/8". How to measure ↓

MagSert Shower Extender on a white background

Shower arm under 5/8"? Add the Extender.

Houses the insert so you still get conditioning. $6.99

Shipping & returns

Ships from the USA, made by MagRock Inc. Unused, uninstalled products in original packaging can be returned within 30 days of purchase. Damaged, defective, or incorrect orders: contact us within 30 days and we'll make it right. See our return policy for full terms.

Will it affect my water pressure?

No. MagSert® sits inside the shower neck and is designed not to restrict your flow — your spray and pressure stay the same.

View full details

You clean the showerhead, and within days the chalky film begins appearing on the nozzles again. That recurring buildup is caused by minerals in the water—not a lack of cleaning.

MagSert® S-640 is a compact, point-of-use water-conditioning insert designed to help make mineral scale easier to manage. It fits inside the shower arm, where water flows through it before reaching the showerhead. With regular use, MagSert® helps reduce the tendency of mineral deposits to adhere and harden on shower nozzles and nearby surfaces. Any deposits that still form may be softer and easier to wipe away.

For the clearest comparison, clean the showerhead before installing MagSert® and observe the results over the following weeks. Results vary depending on water chemistry, mineral concentration, water use, and existing buildup.

What MagSert® is—and what it is not

MagSert® conditions water at the point of use. It is not a water softener or filter, and it does not remove minerals. The minerals remain in the water; MagSert® is designed to help change how mineral deposits form and adhere to surfaces.

No salt. No replacement filters. No electricity. No permanent plumbing changes.

Proudly made in the USA by MagRock Inc.

Simple, easy installation

  1. Unscrew the showerhead from the shower arm.
  2. Insert the MagSert® S-640 into the opening.
  3. Reattach the showerhead.

MagSert® can be removed and taken with you when you move.

Sizing: measure before ordering

The shower arm must have an inside opening of at least 5/8 inch for the MagSert® S-640 to fit. Some shower arms have an inward-facing lip or ridge that makes the usable opening smaller, so measure the narrowest part of the opening rather than relying on the brand or exterior thread size.

Do not force the MagSert® into the shower arm. If the opening is too narrow, the MagSert® Shower Extender provides another installation option and is available as an add-on on this page.

Optional MagSert® Shower Extender

The MagSert® Shower Extender creates a short extension between the shower arm and showerhead. The MagSert® S-640 fits inside the extender, allowing water to flow through it before reaching the showerhead.

To install, place the MagSert® inside the extender, screw the extender onto the shower arm, and then attach the showerhead to the other end. No permanent plumbing changes are required, and the extender and MagSert® can be easily removed when needed. Add it on this page if your shower arm is too narrow for the insert alone.

Get the right fit

One insert — just measure your shower arm first.

Fit is the one thing to get right before you order — it takes about 30 seconds to check.

Measure before you order. The MagSert® S-640 needs a shower arm with an inside opening of at least 5/8". Some shower arms have an inward lip or ridge that makes the usable opening smaller — measure the narrowest point, not the outside thread.

Do not force the insert. If your opening is too narrow, add the MagSert® Shower Extender below — it houses the insert so you still get conditioning.

MagSert® S-640

Fits a shower arm with an inside opening of 5/8" or larger. Measure the narrowest part of the opening.

How to check your size

Measure the inside opening at its narrowest point with a ruler, digital calipers, or our printable sizing guide.

Unscrew the showerhead
Unscrew the showerhead

Expose the threaded shower arm it screws onto.

Measure the inside opening
Measure the inside opening

Lay a ruler across the opening at its narrowest point — you need 5/8" or more. Tip: calipers work too if you have them.

5/8" or larger? Slide it in
5/8" or larger? Slide it in

If the opening is smaller or has an inward lip, don't force the insert — add the Extender below instead.

If your shower arm is under 5/8" or has an inward lip: don't force the insert. Add the MagSert® Shower Extender below — it houses the insert so you still get conditioning, with no filing or plumbing.

When in doubt, measure twice — or contact us before you order.

Add-on

Shower arm under 5/8"? Add the Extender.

The Extender houses the insert so a narrow shower arm still gets conditioning. Here's how it goes on.

MagSert Shower Extender on a white background

Add-on

MagSert® Shower Extender

If your shower neck is too narrow for the insert to sit directly, the Extender houses it so you still get conditioning — no filing, no plumbing. Only needed for narrow necks.

$6.99Only 5 available

The Extender houses the MagSert® Shower insert. It doesn't condition water on its own.

  1. Tape the shower arm
    Tape the shower arm

    With the showerhead off, wrap plumber's tape around the threads on the shower arm.

  2. Thread on the Extender
    Thread on the Extender

    Screw the Extender onto the shower arm and hand-tighten it.

  3. Slide the MagSert in
    Slide the MagSert in

    Drop the MagSert® 640 insert into the Extender. It sits inside the housing.

  4. Tape the Extender threads
    Tape the Extender threads

    Wrap plumber's tape around the Extender's outer threads.

  5. Put the showerhead back on
    Put the showerhead back on

    Screw the showerhead onto the Extender and hand-tighten.

  6. Done
    Done

    The Extender sits between the arm and the head. Run the water and check for drips.

Plumber's tape is included. No tools needed.

Installation

Watch it, or print it.

Prefer to follow along? Watch the step-by-step shower install, or print the instruction sheet and keep it with you.

Watch the shower installation video Opens on YouTube Printable instruction sheet PDF

Buy it once

Built to lastNo parts to wear out
No maintenanceInstall it and forget it
No filtersNothing to replace, ever
No salt, no powerNothing to refill or plug in
One-time installMinutes, no plumber

Our guarantee

Damaged, defective, or not what you ordered? We'll make it right.

Unused, uninstalled MagSert® products in their original packaging can be returned within 30 days of purchase. If your order arrives damaged, defective, or incorrect, contact us within 30 days with your order number and photos — we'll send a replacement, exchange, or refund. Because MagSert® installs directly into your water connection, installed or used products can't be returned. See our full return policy for details.

Made by MagRock Inc. — a family-owned US company. Email us anytime.