Mayset CPA01 4×4 Concrete Post Anchor

Mayset CPA01 is a ground-mounted concrete post anchor for standard nominal 4×4 wood posts, which the listing describes as actually 3.5 × 3.5 inches. Its airflow channel is intended to help keep the post base ventilated, while four L-shaped rebars are designed to grip wet concrete.

At a glance

Designed to be set into wet concrete before it hardens, then fitted with a wood post after the concrete dries.
The bottom airflow channel is intended to ventilate the wood post base and reduce prolonged moisture exposure.
Four L-shaped rebars are intended to anchor the bracket in concrete.
The listing describes a fit for nominal 4×4 posts with actual dimensions of 3.5 × 3.5 inches.

Price

$24.50Save 50%

Reference price: ~~$49.00~~

Price checked: Nov 14, 2026

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Pros and cons

Pros

Airflow channel addresses ventilation at the bottom of a wood post, where moisture may otherwise remain trapped.
Rebars are integrated into the anchor to provide a concrete-gripping feature without relying only on the bracket walls.
The stated post fit distinguishes nominal 4×4 lumber from its listed actual 3.5 × 3.5-inch size.

Technical specifications

10 specifications

Identity and finish
Brand	Mayset
Model	CPA01
Color	Black
Finish	Powder Coated

Dimensions and installation
Mounting type	Ground Mount
Dimensions listed	10 x 3.6 x 3.6 inches
Weight listed	3.7 pounds

Fit and construction
Post fit described	standard 4"x4" (actually 3.5"x3.5") wood posts
Material and coating claim	thickened heavy duty stainless steel with black powder coating
Concrete-grip features	four L-shaped rebars (Φ3/8"; L:4.9")

What to know before buying

Installation is for wet concrete: place the anchor before the concrete sets, then insert the post after curing and secure it through the pre-drilled side holes. Confirm fit against the actual lumber and installation plan before purchase.

What’s in the box

Concrete post anchorIncluded
6 hex screwsCheck selected pack
Drill bitCheck selected pack
Hex socket toolCheck selected pack

Check which accessories are included in your selected pack before buying.

Who is it for?

A good fit for

Fence, deck, porch, or pergola projects using a concrete-set anchor and nominal 4×4 wood posts.
Installers who want a ventilated post base and integrated rebars intended to grip concrete.

Less suited to

Projects needing a surface-mounted anchor added to already-cured concrete, since the stated installation method places it in wet concrete.
Posts other than the listed nominal 4×4 size unless their dimensions have been confirmed to fit.

Mayset CPA01 4×4 Concrete Post Anchor · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.6 / 5 · 7 ratings

5 stars81%81%
4 stars0%0%
3 stars19%19%
2 stars0%0%
1 star0%0%

Only aggregate ratings are available, with a small number of ratings and a distribution concentrated in five-star responses but also including three-star responses. That provides limited reassurance, not a clear account of fit, installation, or durability. For this anchor, verify the post dimensions and concrete-set installation requirements against your project rather than treating the rating as proof of performance.

Frequently asked questions

What size post does the Mayset CPA01 fit?

The listing says it fits standard 4×4 posts, clarified as actual 3.5 × 3.5-inch wood posts. Check the post's measured dimensions before installation.

How is this post anchor installed?

The listed method is to place it in wet concrete before the concrete sets. After the concrete dries, insert the wood post and secure it through the pre-drilled side holes.

What is the airflow channel for?

The listing says the channel at the base allows ventilation beneath the wood post, with the aim of reducing prolonged moisture exposure.

Does the listing state what comes with the anchor?

The product details list a concrete post anchor. A feature bullet separately claims the set contains six hex screws, a drill bit, and a hex socket tool, so check the selected listing for the kit contents.