Size: (Please you can also find more measurement details in the photo) It’s designed a little larger. So you can put the end of the tubing in hot water for a little bit and it will make the tubing go on better.

M01 4mm/8mm to 4mm 2-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 2-way 4mm outlet holes(each outlet holes is with a control valve).
M02 4mm/8mm to 4mm 3-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 3-way 4mm outlet holes(each outlet holes is with a control valve).
M03 4mm/8mm to 4mm 4-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 4-way 4mm outlet holes(each outlet holes is with a control valve).
M04 4mm/8mm to 4mm 5-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 5-way 4mm outlet holes(each outlet holes is with a control valve).
M05 4mm/8mm to 4mm 6-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 6-way 4mm outlet holes(each outlet holes is with a control valve).
M06 4mm/8mm to 4mm 7-Way w/ Valves (Blue) This Aquarium Splitter Connector is 4mm or 8mm inlet hole is divided into 7-way 4mm outlet holes(each outlet holes is with a control valve).
M07 8mm to 4mm 2-Way (Blue) This Aquarium Splitter Connector is 8mm inlet hole is divided into 2-way 4mm outlet holes.
M08 8mm to 4mm 4-Way (Blue) This Aquarium Splitter Connector is 8mm inlet hole is divided into 4-way 4mm outlet holes.
M09 8mm to 4mm 6-Way (Blue) This Aquarium Splitter Connector is 8mm inlet hole is divided into 6-way 4mm outlet holes.
M10 8mm to 4mm 8-Way (Blue) This Aquarium Splitter Connector is 8mm inlet hole is divided into 8-way 4mm outlet holes.
M11 4mm 2-Way Straight(Clear White) Standard with outer diameter: 5mm adapt to 4-5mm air tube; Length: 30mm
M12 4mm 3-Way T-shape(Clear White) Standard with outer diameter: 5mm adapt to 4-5mm air tube; Length: 30mm

Material:
Made of high quality plastic for long-time use, eco-friendly, odorless, 100% free from toxins.

The Plastic Aquarium connector one air intake hole is divided into many air outlet holes to increase the oxygen receiving area of the aquatic product

Great accessories for your fish tank tube, air pump, check valve, bubble stone connection.

Tips: Please pay attention to the correct size before purchase! For a better connection, before you use, please wet the connector and aquarium tube to get a easily install. Please ensure connectors have the hole all the way through.

Hi, dear. Any question please feel free to contact me firstly. I will try my best to help deal with your problems in a short time as soon as I receive your message.