Mansfield by Prier M-123-5035 300 Series 12" Stem Assembly

Copper stem with bright brass coarse threaded end with black rubber washer brass screw metal washer and grey graphite packings.

Complete 300 series faucet picture with grey handle polished chrome body copper tube and brass end.

WHAT OUR CUSTOMERS SAY…

“Super fast shipping and reasonable shipping fee. Will definitely use again. ”

-Bill K.

06/02/2026

$47.87

This item is a complete replacement stem assembly for the “original style” 300 series Mansfield wall hydrants (manufactured between 1970 and 2013), made by Prier Products.

We can ship anywhere the US Postal Service ships. For orders being shipped outside the US, please contact us at (888) ASK-NOEL, noelsplumbingsupply@fuse.net, or via the text widget on this screen.

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Mansfield Stem Assembly for 12″ Series 300 Hydrant

M-123-5035

The stem assembly has an overall length of 15 7/8 inches.
It is specifically designed for an 12-inch wall depth, measured from the back of the face plate to the water shut-off. It replaces the stem in a 378-08 or 379-08 hydrant.
The packaging includes the stem assembly, a metal O-ring, a support washer, and both left-hand (large flat) and right-hand (small thick) graphite packings to accommodate different faucet types.

Related Documents

300 Series Faucet Parts Breakdown

UPC: 670210370165

Customer submitted images.

Common questions about this product

Yes, this is the OEM recommended part.

If you’re not sure text us a picture 1-888-275-6635 or email us a picture at noelsplumbingsupply@fuse.net.

We will make sure you have the right part.

WHAT OUR CUSTOMERS SAY…

“This place is amazing. I live in San Antonio, Texas and there are a few plumbing stores with vintage parts but they never have what I need and the ordering process takes them weeks. I found a rare part at Noels by reverse image search but they will do it for you. I've used them 3 times. Their agents are knowledgable and polite. They will find you the same part or the after market part and get you going on your way. They have 2-3 day shipping. My house was built in the 30's and they know exactly what the after market parts are that I need. I save money and time going to them. I sure wish they were in San Antonio! I will just go directly to Noel's next time - they are LEGENDS! ”

-BP W.

06/21/2026