Bluelab® Guardian Monitor

Marsoni

M251S

$205.50

Get it in 3 business days with 1 day shipping. Friday, May 29

Bluelab® Guardian MonitorAdjustable brightness display. Large easy to read, plant safe green LED displays. Selectable values for conductivity and temperature. Simple push button pH calibration system. No calibration required for conductivity and temperature. Silent alarm for both high and low settings. Settings retained when power lost (non volatile memory). Temperature compensation. An international power supply. Water resistant design. 2 year Bluelab Guarantee (6 months on

Easy Shipping

Quick Dispatch:

Your Bluelab® Guardian Monitor orders ship within 1-2 business days.

Delivery Options:

Standard: 3-7 business days
Fast: 2-3 business days
Express: 1-2 business days

Order Tracking:

You'll receive a tracking link by email once your Bluelab® Guardian Monitor ships.

Need Help?
Questions about Bluelab® Guardian Monitor, sizing, or delivery? We're just an email away.

Live Shipping Estimates:
Enter your location at checkout to see available shipping methods and costs for Bluelab® Guardian Monitor in your area.

Get Shipping Estimates

Country Zip/Postal Code

Exchange/Return Notes

We offer a 30-day return/exchange service after receiving.
Final sale items are not eligible for returns or exchanges.
To process your return/exchange, please contact us at [email protected]
Please click here for more details>>> Return & Exchange Policy

Wonderful Product!!! The balls themselves are amazing and the squeaker in them my dog loves. I am giving them only a three star because they arrived and they SMELL like chemicals so bad!!! I was afraid to give it to my dog so i washed one out and put it up hoping the chemical smell will go away. This not good for a dog as unknown chemicals can make them really sick. Whatever amazon is spraying on their stuff it's not good

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on April 1, 2025

Verified Purchase

Brandi G

Phoenix, US

★★★★★ 5

Puppy tested & approved

Color: 12 Tennis Ball

I ordered these squeaky tennis balls for my cocker spaniel. She absolutely loves these tennis balls with the squeakers in them! She plays with them all day, and chews on them frequently. We have not had any problems with her, breaking the tennis balls, which is generally the issue we have with her. The tennis ball fuzz stays on the ball very well, which is usually an issue with standard tennis balls, because my dog likes to peel off the yellow fuzz on all tennis balls. She has not been able to do that with these. I will definitely be buying these again , but will not need to anytime soon as these are extremely well built.

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on October 25, 2022

Verified Purchase

Kindle Customer

Battle Creek, US

★★★★★ 5

My dogs love these things

Color: 12 Tennis Ball

My dogs love these things. I think I bought it twice now.

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on January 15, 2026

Verified Purchase

TNEarthMAMA

Lake Worth, US

★★★★★ 5

Dog toy that lasts.

Size: 5 Pack

I've got a heavy chewer on my hands, so I've basically thrown money away on countless "durable" toys that get shredded in minutes. I was skeptical about these, but the "no stuffing" design caught my eye—at least there wouldn't be fluff all over my living room! I'm happy to report that these have actually lasted! My dog loves shaking them around and making them squeak. The crinkle sound is a huge bonus; it really keeps him engaged. The fact that they're lightweight makes them perfect for a game of fetch, and my dog can easily carry them around. For the price, getting a whole bundle of these is a great deal. If you're tired of cleaning up toy stuffing, I'd definitely recommend giving these a try.

WAS THIS REVIEW HELPFUL?YesReportShare

Reviewed in the United States on March 18, 2026