Skip to content

Your cart is empty

Continue shopping

Have an account?

Log in to check out faster.

Your cart

Loading...

Order special instructions

Subtotal

$ 0.00 USD

Taxes and shipping calculated at checkout
  • Home
  • Product Search
  • Benefits
    • Benefits
    • Testimonials
  • Discount Bundles
    • All Bundles
    • M4
    • M6
    • M4 + Agitator
    • M4 18-20V (DeWalt, Milwaukee, etc.)
    • M4 upgrade kits
      • Agitator upgrade kit
      • Battery upgrade kit
      • Electrical upgrade kit
    • M2
  • Parts & Accessories
    • New Products
    • Valve Handle Trigger
    • Batteries
    • Wands
    • Pumps
    • Nozzles
    • HYDRAULIC
      • WANDS (14ft telescoping, 4 boom, etc))
      • HOSE (15ft, Coiled, Standard, Elbow, etc)
      • NOZZLES (QR, Flexi, Fan, Cone, , Multinozzle, etc)
      • VALVES/PISTOLS
      • QUICK RELEASE/WASHERS/O-RINGS/ADAPTERS
      • Washers/O-rings
      • Quick Release
      • Adapters
    • ELECTRIC
      • Pumps
      • Switches
      • Batteries
    • STRUCTURAL
      • Lid
      • Filters
      • M4 Pockets and storage
      • Straps/Buckles
      • Base plate screws
      • Tanks
  • Videos
    • Videos
    • New Customer
      • Quick start
      • Overview of parts shipped with the M4 Backpack Sprayer
      • Nozzle kit Overview
      • Assembly and final inspection
      • My4sons Quality Care
      • Top 10 reasons why the MY4SONS M4 is rated #1 on amazon
      • M4: Charging and rotary switch use
      • How to prime the M4 Backpack Sprayer using A garden Hose
    • New For 2026
      • New For 2026
      • Monster Cart
    • Part/Accessories
      • 14 ft telescoping wand video
      • 14ft telescoping wand adapting to other sprayers
      • M4 New super wide XXL water Tight Lid Seal
      • Wide Lid Preview
      • Spray Pistol
    • Electric
      • New Wireless Remote Control for the M4!
      • 2021 Electrical Upgrade Kit
      • Battery and Multimeter
    • Troubleshooting
      • Quick Fix#1 no power, no voltmeter lights
      • Quick Fix #2 no power but voltmeter lights on
      • 5 step diagnostic checklist
      • M4: Charging and rotary switch use
      • Is my battery good?
      • Solving a collapsing tank
    • Maintenance
      • The best way to wire the M4
      • Securing Shoulder Strap anchor screw
      • Changing the red valve handle piston
      • Getting rid of leaks
      • How to prime the M4 Backpack Sprayer
    • Part Replacement
      • Replacing the pump
      • Replacing a broken pump neck
      • Replacing the red and rotary switches
  • About Us and FAQ
    • A Message From Our Founder
    • Assembly and final inspection
    • Customer Testimonials
    • Contact us
    • FAQ
Log in
    MY4SONS
    • Home
    • Product Search
    • Benefits
      • Benefits
      • Testimonials
    • Discount Bundles
      • All Bundles
      • M4
      • M6
      • M4 + Agitator
      • M4 18-20V (DeWalt, Milwaukee, etc.)
      • M4 upgrade kits
        • Agitator upgrade kit
        • Battery upgrade kit
        • Electrical upgrade kit
      • M2
    • Parts & Accessories
      • New Products
      • Valve Handle Trigger
      • Batteries
      • Wands
      • Pumps
      • Nozzles
      • HYDRAULIC
        • WANDS (14ft telescoping, 4 boom, etc))
        • HOSE (15ft, Coiled, Standard, Elbow, etc)
        • NOZZLES (QR, Flexi, Fan, Cone, , Multinozzle, etc)
        • VALVES/PISTOLS
        • QUICK RELEASE/WASHERS/O-RINGS/ADAPTERS
        • Washers/O-rings
        • Quick Release
        • Adapters
      • ELECTRIC
        • Pumps
        • Switches
        • Batteries
      • STRUCTURAL
        • Lid
        • Filters
        • M4 Pockets and storage
        • Straps/Buckles
        • Base plate screws
        • Tanks
    • Videos
      • Videos
      • New Customer
        • Quick start
        • Overview of parts shipped with the M4 Backpack Sprayer
        • Nozzle kit Overview
        • Assembly and final inspection
        • My4sons Quality Care
        • Top 10 reasons why the MY4SONS M4 is rated #1 on amazon
        • M4: Charging and rotary switch use
        • How to prime the M4 Backpack Sprayer using A garden Hose
      • New For 2026
        • New For 2026
        • Monster Cart
      • Part/Accessories
        • 14 ft telescoping wand video
        • 14ft telescoping wand adapting to other sprayers
        • M4 New super wide XXL water Tight Lid Seal
        • Wide Lid Preview
        • Spray Pistol
      • Electric
        • New Wireless Remote Control for the M4!
        • 2021 Electrical Upgrade Kit
        • Battery and Multimeter
      • Troubleshooting
        • Quick Fix#1 no power, no voltmeter lights
        • Quick Fix #2 no power but voltmeter lights on
        • 5 step diagnostic checklist
        • M4: Charging and rotary switch use
        • Is my battery good?
        • Solving a collapsing tank
      • Maintenance
        • The best way to wire the M4
        • Securing Shoulder Strap anchor screw
        • Changing the red valve handle piston
        • Getting rid of leaks
        • How to prime the M4 Backpack Sprayer
      • Part Replacement
        • Replacing the pump
        • Replacing a broken pump neck
        • Replacing the red and rotary switches
    • About Us and FAQ
      • A Message From Our Founder
      • Assembly and final inspection
      • Customer Testimonials
      • Contact us
      • FAQ
    Log in Cart
    • M4 Shoulder Straps (Pair) Extreme Duty 4X Polyester with Triple Thick Padding

      M4 Shoulder Straps (Pair) Extreme Duty 4X Polyester with Triple Thick Padding

      Sale

      M4 Shoulder Straps (Pair) Extreme Duty 4X Polyester with Triple Thick Padding

      Regular price $ 24.99 USD
      Regular price $ 29.99 USD Sale price $ 24.99 USD
      Unit price /  per 
      Sale
    • BATTERY DOOR

      BATTERY DOOR

      Sale

      BATTERY DOOR

      Regular price $ 1.99 USD
      Regular price $ 4.99 USD Sale price $ 1.99 USD
      Unit price /  per 
      Sale
    • M4 Wand Pocket (SEE CAUTION!)

      M4 Wand Pocket (SEE CAUTION!)

      Sold out

      M4 Wand Pocket (SEE CAUTION!)

      Regular price $ 7.99 USD
      Regular price $ 9.99 USD Sale price $ 7.99 USD
      Unit price /  per 
      Sold out
    • Liquid Level Sticker

      Liquid Level Sticker

      Liquid Level Sticker

      Regular price $ 0.99 USD
      Regular price Sale price $ 0.99 USD
      Unit price /  per 
    • M4 Base Plate

      M4 Base Plate

      Sale

      M4 Base Plate

      Regular price $ 7.99 USD
      Regular price $ 9.99 USD Sale price $ 7.99 USD
      Unit price /  per 
      Sale
    • Heavy Duty Steel Buckle For M4 Shoulder Pads 2 For

      Heavy Duty Steel Buckle For M4 Shoulder Pads 2 For

      Sale

      Heavy Duty Steel Buckle For M4 Shoulder Pads 2 For

      Regular price $ 2.99 USD
      Regular price $ 4.99 USD Sale price $ 2.99 USD
      Unit price /  per 
      Sale
    • Strap hook pair for shoulder pad anchor

      Strap hook pair for shoulder pad anchor

      Strap hook pair for shoulder pad anchor

      Regular price $ 1.99 USD
      Regular price Sale price $ 1.99 USD
      Unit price /  per 
    • Cart Bag (Fits Most Hand Trucks)

      Cart Bag (Fits Most Hand Trucks)

      Sale

      Cart Bag (Fits Most Hand Trucks)

      Regular price $ 14.99 USD
      Regular price $ 29.99 USD Sale price $ 14.99 USD
      Unit price /  per 
      Sale
    • 1
    • 2

    Subscribe to our emails

    Promotions, new products and sales. Directly to your inbox.

    Quick links

    • Search
    • User Manual For The M4
    • About / Contact
    • Troubleshooting/FAQ
    • Agitator installation paper work

    Final assembly and quality tested in the USA

    2 Year Warranty — 30 day returns for unused items minus the cost of shipping. / Patents Pending. / Please note that the M4 system is not compatible with muriatic acid.

    Payment methods
    • Amazon
    • American Express
    • Apple Pay
    • Diners Club
    • Discover
    • Google Pay
    • Mastercard
    • PayPal
    • Shop Pay
    • Visa
    © 2026, MY4SONS Powered by Shopify
    • Refund policy
    • Privacy policy
    • Terms of service
    • Choosing a selection results in a full page refresh.
    • Opens in a new window.