Aftermarket · Made by Think Crucial · Not made by Dolphin

Ultra-fine filter panels for Maytronics Dolphin pool robots.

Four large ultra-fine panels, part 9991432-R4, for the Nautilus CC Plus, M200, M400, M500 and more. 4 panels for $24.99, $6.25 a panel.

Maytronics sells its 9991432-R4 4-pack at $49.99. Ours: $24.99, $25.00 less.

4.7from 9 ratings on Amazon(as of Oct 5, 2026)

Think Crucial filter panel for the Dolphin Dolphin · 9991432-R4 — **Fig. 01**4 panels

The mathmaytronics.com · October 6, 2026

Maytronics 9991432-R4 4-pack at $49.99$49.99
Think Crucial 4-pack$24.99

You pay less by$25.00

Dolphin list price on maytronics.com (Maytronics' own store) on October 6, 2026, before any sale, coupon or subscription discount.

Shipping
Free U.S. shipping on every order
Dispatch
Ships the same business day when ordered by 2pm ET
Fit
Fit guaranteed on the models listed
Returns
30-day returns with a prepaid label

01How it comparesPrices dated

Think Crucial vs. buying from Dolphin.

The same count, side by side. Dolphin's price is its list price on maytronics.com on October 6, 2026.

Dolphin · 9991432-R4	Think Crucial	Dolphin, same count
4 panels	$24.99$25.00 less	$49.99
Subscription	None. Buy when you need panels	Dolphin's own terms
If it doesn't fit	Prepaid return label, full refund, 30 days	Dolphin's own terms
Made by	Think Crucial (aftermarket)	Dolphin

Dolphin price: Maytronics 9991432-R4 4-pack at $49.99, $49.99, on maytronics.com (Maytronics' own store) on October 6, 2026, before any sale, coupon or subscription discount.

02Spec sheetFrom the listing

What's in the box.

Exactly what ships, so you can match it against what's in your machine now.

In the box4 panels

4 ×
large ultra-fine filter panels
part 9991432-R4

Fits: Dolphin Ultra, Nautilus CC Plus, M200, M400, M500, M4, M5, Wave 65, Wave 90 and Oasis Z5
Replaces part no.: 9991432-R4 (Dolphin)
Price: 4 panels: $24.99
Subscription: None. Buy when you need it
Made by: Think Crucial (aftermarket, not affiliated with Dolphin)
Ships: Free, from a U.S. warehouse. Same business day when ordered by 2pm ET; arrives in 2–5 business days

03From Amazon4.7 / 5 · 9 ratings

What owners say.

Reviews of this filter panel on Amazon.com, quoted word for word. Rated 4.7 out of 5 from 9 ratings as of October 5, 2026.

★★★★★

“Works great I'm my dolphin. I buy new ones every season. These will trap everything including super fine sand.”

Verified purchase · Amazon.com · Jun 30, 2024

★★★★★

“Plug and play.”

Verified purchase · Amazon.com · Jun 17, 2024

★★★★★

“Very good”

Verified purchase · Amazon.com · Aug 1, 2025

04CompatibilityDolphin · 9991432-R4

Check your model.

Listed for the Dolphin Ultra, Nautilus CC Plus, M200, M400, M500, M4, M5, Wave 65, Wave 90 and Oasis Z5. Two minutes now saves a return later.

Dolphin Ultra
Nautilus CC Plus
M200
M400
M500
M4
M5
Wave 65
Wave 90
Oasis Z5

01
Find the model
Your Dolphin's model is on the label on the robot body or the power supply.
02
Check the filter type
These are panel filters. Robots that use a filter basket or cartridge take a different filter.
03
Still not sure?
Email your model number to support@thinkcrucial.com and we'll tell you whether it fits. We reply within one business day.

05QuestionsBefore you order

Before you order.

Straight answers. Anything else, email support@thinkcrucial.com.

Q.01Is this made by Dolphin?

No. It's a compatible replacement made by Think Crucial. It isn't made, sold or endorsed by Dolphin, and Think Crucial isn't affiliated with Dolphin.

Q.02Are these panels or a basket?

Panels: four large ultra-fine filter panels, part 9991432-R4.

Q.03How many come in the pack?

Four panels, $6.25 a panel.

Q.04What if it doesn't fit?

Fit guaranteed: if it doesn't fit the model we list, email support@thinkcrucial.com within 30 days of delivery with your order number and model number. We send a prepaid return label and refund you in full, even if you opened it to test the fit. Changed your mind? Return it unused, in its original packaging, within 30 days of delivery.

Q.05Is there a subscription?

No. You buy when you need it. Nothing renews and nothing auto-ships.

Q.06When will it arrive?

Free U.S. shipping on every order, from a U.S. warehouse. Ships the same business day when ordered by 2pm ET. Arrives in 2–5 business days.

06Who makes this

We make what we sell.

Think Crucial started in 2007 at a family vacuum repair shop. Today we're a U.S. company in Hollywood, Florida, making aftermarket filters, bags and parts built to fit the machines you already own. Most people can fit the part themselves. They just need the right one, and a way to check it first.

Questions before you order? Email support@thinkcrucial.com. We reply within one business day.

Ready to order