Free 1-2 Day Shipping. Low Price Guarantee. Easy Returns/Exchanges.

Choose from top models from the top brands.

Free 1-2 Day Shipping. Low Price Guarantee. Easy Returns/Exchanges.

Choose from top models from the top brands.

Free 1-2 Day Shipping. Low Price Guarantee. Easy Returns/Exchanges.

Choose from top models from the top brands.

Dolphin M400

  • Easy Access Filter - Top-load filter access for easy and convenient debris removal and cleaning
  • MyDolphin Plus Mobile app - Smart control of your Dolphin - Anytime, Anywhere
  • Waterline Scrubbing - Super efficient on vertical surfaces for optimal waterline scrubbing
  • Weekly scheduler - Customize your weekly schedule cleaning times to fit your needs
  • Energy Saver - Reduces water, chemical, and energy usage with every pool cleaning

Shoppers ultimately bought... Compare vs.

Dolphin Sigma

Sigma adds waterline cleaning, NanoFilters™, triple motors, gyroscope, 3 year warranty + 30 Day Free Trial.

Dolphin Premier

Premier adds waterline cleaning, commercial grade motors, MultiMedia™, NanoFilters™, 3 year warranty + 30 Day Free Trial.


M400 Product Video

Try Risk-Free for 30 Days

Buy with Confidence

Try any robot in your pool risk-free for 30 days. We believe a pool robot is an investment, and we know you'll love it. Which is why we have a 30 Day Free Trial. If you don't love it, simply return the robot. Unlike the other guys, we never charge a restocking fee or any other fees - meaning no restocking fee ever.

Here at Poolbots, we carry only the top models for the top brands. All of our pool robots are backed by a full manufacturer's warranty - not prorated or limited to cycles like other pool robots.

M400 Accessories

Dolphin Universal Caddy

Easily transport your Dolphin M400 with the Dolphin Universal Caddy. Fits any Dolphin Robotic Pool Cleaner.

Dolphin M400 Specifications

Waterline Cleaning No
Wall Climbing Yes
Dual Stabilizer Yes
Number of Motors 2
Gallons Filtered Per Hour 4500 GPH
Filter Types Top Access
Pool Coverage Floor, Walls and Waterline
Pool Types In Ground
Pool Size 50 ft
Pool Shapes Rectangle, Oval, or Freeform
Pool Surfaces Gunite, Fiberglass, Vinyl, Liner
Cable Length 60 ft
Anti-Tangle Swivel Yes
Obstacle Avoidance Steps, Ladder, Drain Cover, Ledges, Pop-Ups
Warranty 3 Years
Brand Dolphin
Manufacturer Maytronics
Part Number 99991046-USI

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Questions and Answers

Does Poolbots charge any restocking fees in your 30 Day Free Trial?

No, we never charge a restocking fee ever! We know a robotic pool cleaner is a big investment, which is why we offer Free 30-Day Trials on all robotic pool cleaners!

How long is the Dolphin M400's warranty?

As a proud Authorized Dealer for Dolphin, the Dolphin M400 includes a full 3 year warranty from date of purchase.

Does Dolphin M400 need a booster pump to work?

No! The Dolphin M400 is plug and play! All you need to do is unbox the unit and plug it into an outlet. No setup or assembly required!

My Dolphin M400 gets stuck on drains, how can I fix this?

With a main drain clip on, you can successfully avoid the robot getting stuck on your drain.

Does the Dolphin M400 work with saltwater pools?

Yes. The Dolphin M400 works with all types of pools, including freshwater and saltwater.

What types of pools does the Dolphin M400 work with?

The Dolphin M400 is compatible with the following types of pools: In-ground pools, above-ground pools, gunite pools, tile pools, fiberglass pools, and viny pools of all shapes and sizes. If you have any questions or wonder if this is the right robot for you, contact us or view our Pool Robot Guide.

Does the Dolphin M400 have WiFi/Bluetooth?

Yes, the Dolphin M400 has wifi and bluetooth that allows you to connect and control the robot from the app.

Does the Dolphin M400 have an app?

Yes, the Dolphin M400 has an app to control the robot.

How long does Nautilus CC Plus run for?

The Dolphin M400 cleans for 2.5 hours. You can set the robot to run daily via its included programmable timer.

How much does Dolphin M400 weigh?

The Dolphin M400 weighs 26.967 lb.

How does Dolphin M400 work?

The Dolphin M400 works as an automatic robotic pool cleaner. It will vacuum, scrub, and automate your pool cleaning. With a plug and play design, all you need is an outlet to plug it into and you’re good to go. No booster pump or assembly needed.

Does Dolphin M400 pick up leaves?

The Dolphin M400 can pick up leaves. While not as effective as the Dolphin Premier, which includes an oversized leaf bag.

Does Dolphin M400 pick up sand, algae, or small debris?

The Dolphin M400 cannot perform as well as robots with NanoFiltration. As the mesh filters on Dolphin M400 cannot capture small particles like the newer Gen-2 NanoFilters. See all robots with NanoFiltration here.

Does Dolphin M400 come with NanoFilters?

The Dolphin M400 does not have NanoFilters. See all robots with NanoFilters here.

Does Dolphin M400 clean waterline?

Yes, the Dolphin M400 cleans the waterline.

Does Dolphin M400 climb walls?

Yes, the Dolphin M400 cleans your entire pool - including the floor, walls, and waterline.

Can the Dolphin M400 be plugged into an extension cord?

Yes it can!

I can power my Dolphin M400 on but it does not move

If your Dolphin powers on but does not move, try checking the tracks for any debris or obstructions. Also, check the drive motor and impeller for any damage or wear. If you are still having issues, contact Maytronics customer support for further assistance.

My Dolphin M400's power supply does not turn on when I press the power button

If your Dolphin's power supply is not turning on, check to make sure it is properly plugged in and that the outlet it is plugged into is working. If the power supply is still not turning on, contact Maytronics customer support for further assistance.

My Dolphin M400 is not cleaning the pool properly

If your Dolphin M400 is not cleaning the pool properly, try checking the filter bag for any debris or blockages. Also, check the brushes and tracks for any damage or wear. If you are still having issues, contact Maytronics customer support for further assistance.

What are the handles and the floats on my Dolphin for?

The handles on your Dolphin are for lifting and carrying the unit, while the floats are designed to help your Dolphin navigate around the pool and maintain proper buoyancy.

There seems to be something stuck in my Dolphin M400's' tracks – how can I get it out?

To remove any debris or obstructions from your Dolphin's tracks, turn off the power supply and carefully remove the tracks from the unit. Use a soft brush or cloth to clean the tracks and remove any debris. Once clean, reattach the tracks to the unit.

The cord is connected to the robot's power unit, but the power unit LED indication is off.

If the power unit LED indication is off even when the charger is connected, please try the following steps: 1) Unplug the power supply from the outlet and wait for 10 seconds. 2) Plug the power supply back in and check if the LED indication turns on. 3) If the LED indication still does not turn on, contact Maytronics customer support for further assistance.

Why should I register my robot?

Registering your Dolphin robotic pool cleaner allows you to receive important product updates and notifications, as well as access to exclusive content and promotions.

What's Next?

Learn more about Nanofilters™, MaxBin™, and so much more to find which pool robot is right for you. Use our Pool Robot Selector to enter your pool type and find an exact match for your swimming pool's needs or read the Best Dolphin Pool Cleaner for 2024.