The Momcozy V2 Pro takes the Momcozy V1 Pro and V2 Pro duckbill valves (4-pack) (part AS158-NA71NB-A) as its valve; replace it every 3 months; Australian sellers list it from A$3.26 each as of 28 October 2026. Fitment confirmed against the manufacturer's compatibility list.
Your breast pump
Momcozy V2 Pro
Breast pump
Confirmed against Momcozy's listConfirmed against Momcozy's own compatibility list
Not yours? ChangeSave it · remind me every 3 months
Takes the AS158-NA71NB-A valve
V1 Pro and V2 Pro duckbill valves (4-pack) · replace every 3 months · check the code on your old part before ordering.
Your breast pump
Breast pump
Confirmed against Momcozy's listConfirmed against Momcozy's own compatibility list
Takes the AS158-NA71NB-A
Valve · every 3 months · check the code on your old part.
Other Momcozy breast pumps that take the AS158-NA71NB-A
GenuineGenuine Momcozy
$5.25 each
4-pack $20.99
Momcozy Australia · 1 NovLowest genuine · Momcozy Australia · checked 1 Nov
CompatibleCompatible option
$3.26 each
6-pack $19.57
Amazon AU · 28 OctAmazon AU · checked 28 Oct
Check sellerCheck seller details
Genuine: made by Momcozy. Compatible: another brand.Genuine is made by Momcozy. Compatible is made by another brand. Check the seller's page for the size and models it fits.
Lowest compatibleLowest compatible price · $3.26 each · 6-pack $19.57
Amazon AU. Compare with genuine below. Some links earn us a commission. Some seller links earn us a commission, at no extra cost to you.
Other parts this breast pump takes
- Momcozy V1 Pro and V2 Pro double-pumping tubingOpen Momcozy Australia$15.99
The tubing. Separate from the valve.
- Momcozy V1 Pro and V2 Pro single-pumping tubingOpen Momcozy Australia$15.99
The tubing. Single-pumping tube, if you pump one side at a time Separate from the valve.
Compare 2 sellers
AUD, before delivery. Each price shows when it was checked.
Compatible options
1 seller
Opens Amazon AU in a new tab. Their page is the source of truth for price, delivery and returns.
Not due yet?
Get a nudge when your valve is due — it's every 3 months. One email two weeks before, no newsletter. Manage or stop it anytime.
How to change the valve in your Momcozy V2 Pro
Watch the guide or follow the steps.
No clear video for this part yet. The steps cover it.
- 1Wash your hands, take the pump off and separate the milk collector, flange and silicone parts.
- 2Remove the old duckbill valve and check the other silicone parts for cracks, tears or stretching.
- 3Before first use, wash the new duckbill valve and boil it for 5 to 10 minutes, then let it air dry.
- 4Fit the new duckbill valve in the same place as the old one, so it sits snugly and lies flat.
- 5Reassemble the pump and check for leaks or low suction before pumping.
Every number this part goes by
- Retail name:
- AS158
- Retail name:
- AS158-NA71NB-A
- Retail name:
- Momcozy V1 Pro duckbill valve
- Retail name:
- Momcozy V2 Pro duckbill valve
- Retail name:
- V1 Pro duckbill
- Retail name:
- V2 Pro duckbill
Sellers list any of these; they are the same part.
About your Momcozy V2 Pro
Momcozy breast pump — V series. Its valve is the V1 Pro and V2 Pro duckbill valves (4-pack), part AS158-NA71NB-A, changed every 3 months.
Also in this breast pump:
- Momcozy V1 Pro and V2 Pro double-pumping tubing.
- Momcozy V1 Pro and V2 Pro single-pumping tubing. Single-pumping tube, if you pump one side at a time.
Where the model number is: The model name is printed on the motor unit or its base, and on the box. Wearable pumps also show it in the maker's app.
Common questions
- Which valve fits the Momcozy V2 Pro?
- The Momcozy V2 Pro takes the Momcozy V1 Pro and V2 Pro duckbill valves (4-pack) (part AS158-NA71NB-A).
- How often should I replace the valve in my Momcozy V2 Pro?
- Every 3 months, or sooner if it looks worn.
- Where can I buy the AS158-NA71NB-A in Australia?
- We track 2 Australian sellers for the AS158-NA71NB-A; the lowest listed price when we last checked was A$3.26 at Amazon AU. Prices are re-checked daily and dated on this page.
- How do I fit the AS158-NA71NB-A in a Momcozy V2 Pro?
- No tools, a few minutes: 5 steps, listed on this page with the replacement video where the maker has one.
- What happens if I don't change it?
- A stretched or torn valve or membrane lets the suction drop, so each session takes longer.
- Is there anything to reset afterwards?
- No reset: the pump has no reminder for this part, so set your own.
Something looks wrong with the V2 Pro match? . Reports go to a person, not a bot.