will this tubing fit the 40 mil. airstone?

No It will not 40 Mil. Is way to big. That is 1.75 inches round. However 4 mil is a bit under 1/4 inch. A 1/4 inch is equal to about 6 mill I would say that This tube is 6 mil and it fits real tight over the 1/4 inch fitting of the air pump. So much so I had to Chew the end to loosen it, Then shove it on. It works.

I use aquarium tubing to siphon gas out of my snow blower into my lawn mower in the spring time. Then I make sure it is drained and left out in the sun to evaporate out, then I throw it away. My guess is that this tubing should work well for short minutes of durations like that and then make sure it has at least a week chance to dry out before disposing of it. I would never use tubing not rated for gas lines to fix a gas line on a lawn mower or anything like that.

if my air pump fails, will all the water back-flow and flood the room?

If your pump fails in a very unusual manner, such that both check valves fail, and if it continues to pump with the outlet check valve actually functioning backwards, then it is remotely possible that the water could backflow into the room. But... none of that happens in real life; it only happens in comic books. If your pump fails, it will just stop pumping but both check valves will remain intact so the air line will continue to hold some small amount of pressure until you notice that all your fish are dead and your tank is sans bubbles. In order to start a siphon, which might drain your tank, there would need to be a fair quantity of water in the tubing OUTSIDE your tank, the weight of which will draw suction. What's more, that fair quantity of external water needs to be BELOW the (top) surface of the water in your tank. So... for all intents and purposes... no. It's not going to happen.

will this tubing fit on 4mm(air stone) and 5mm(check valve) outer diameter connections?

It will not. It might fit on 3.5mm fittings, because that's the inside diameter of this tubing.

Deliver to EGYPT

For best experience Get the App

DOWNLOAD THE APP

WE SOURCE ITEMS FROM

UAE
UK
India
USA
Japan
KOREA

Customer Services

About Us

Customer Support

Penn-Plax Standard Airline Tubing for Aquariums – Clear and Flexible – Resists Kinking – Safe for Freshwater and Saltwater Fish Tanks – 25 Feet

Penn-Plax Standard Airline Tubing for Aquariums – Clear and Flexible – Resists Kinking – Safe for Freshwater and Saltwater Fish Tanks – 25 Feet

Product ID: 829228

Secure Transaction

Details

Brand
Penn-Plax
Material
Plastic
Color
Clear
Product Dimensions
3.25"L x 1.5"W
Item Weight
0.11 Kilograms
Maximum Pressure
55 Pound per

🌊safe for fresh & saltwater

💪kink-resistant durability

📏25 feet length

Description

📏💧 Keep your tank breathing easy with tubing that’s as flexible as your aquatic ambitions!

BUILT TO LAST - Flexible yet tough plastic resists kinks, cracks, and brittleness—ensuring long-term reliability.
FISH SAFE ASSURANCE - Non-toxic, aquarium-safe material supports healthy environments in both freshwater and saltwater tanks.
UNIVERSAL COMPATIBILITY - Perfect 3/16” (4mm ID, 6mm OD) size fits air pumps, air stones, and filters with ease.
SEAMLESS AQUARIUM INTEGRATION - Ultra-clear tubing virtually disappears underwater for a sleek, professional look.
GENEROUS LENGTH FOR VERSATILITY - A full 25 feet of tubing means you’re always ready for upgrades, expansions, or emergency replacements.

Penn-Plax Standard Airline Tubing offers 25 feet of clear, flexible, and kink-resistant plastic tubing designed for aquarium use. With precise 3/16” dimensions, it ensures secure connections for air pumps and accessories in both freshwater and saltwater tanks, providing durable, fish-safe performance that blends invisibly into your aquatic setup.

Specifications

Brand	Penn-Plax
Material	Plastic
Color	Clear
Product Dimensions	3.25"L x 1.5"W
Item Weight	0.11 Kilograms
Maximum Pressure	55 Pound per Square Inch
Nominal Wall Thickness	1 millimeter
Outside Diameter	6 Millimeters
Item Length	25 Feet
UPC	030172350252
Manufacturer	Monster Pets
Specific Uses For Product	Indoor
Global Trade Identification Number	00030172350252
Part Number	ST25
Item Weight	3.87 ounces
Item model number	ST25
Is Discontinued By Manufacturer	No
Size	25 Feet
Style	Plastic
Pattern	25 Feet
Shape	Round
Item Package Quantity	1
Included Components	Penn-Plax Standard Airline Tubing for Aquariums – Clear and Flexible – Resists Kinking – Safe for Freshwater and Saltwater Fish Tanks – 25 Feet
Batteries Included?	No
Batteries Required?	No
Warranty Description	Warranty

Common Questions

Are the products genuine and authentic?+

Yes, all products are sourced directly from authorized retailers in the US, UK, UAE and India. We maintain strict quality control processes and verify each product before shipping. All items come with applicable manufacturer warranties and are covered by our standard return policy.

How long does delivery take and is it reliable?+

Delivery times vary by destination country, typically ranging from 3-9 business days. Each order is fully trackable through our system. We handle all customs clearance and use reliable courier partners for last-mile delivery. You'll receive regular updates about your order status via email and our app.

What is Desertcart? Is it safe to order from?+

Desertcart is an international e-commerce platform operating since 2014. We securely process thousands of orders globally each day. Every product goes through our quality verification process before delivery, and we provide end-to-end order tracking, 24/7 customer support, and a comprehensive returns policy to ensure a safe shopping experience.

How is product pricing calculated?+

Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Suresh K.

Very impressed with the quality and fast delivery. Will shop here again.

4 days ago

Neha S.

Excellent communication throughout the order process. Product is perfect.

2 weeks ago

View all Trustpilot reviews

Shop Global, Save with Desertcart

Value for Money

Competitive prices on a vast range of products