Watertight Enclosure End Caps and Flange Caps (2″ Locking Series)


End caps and flange caps for the 2″ Series Watertight Enclosure. These are the second generation of these caps and flange caps with precision machined O-ring interfaces, a locking cord, anti-rotation feature, and optional M10 threaded holes for cable penetrators. Rated to depths up to 950 meters.

If you’re looking for a complete underwater enclosure, check out the Watertight Enclosure Configuration page.

HS Code: 3923.50.00

Product Description

A variety of end cap and flange cap options for the 2″ Series Watertight Enclosure allow you to customize your enclosure for your application. End caps require an O-ring sealing flange to be installed on the enclosure and flange caps have the O-ring sealing flange built-in so that one is not necessary.

The clear acrylic end cap and dome end cap offer optically clear ports for cameras, lights, and other applications where optical clarity is important. They install to the O-ring sealing flange with six included screws.

The flange caps are anodized aluminum and include the same features as the O-ring sealing flange including dual radial O-rings for reliable high-pressure sealing, a locking cord gland, and an anti-rotation feature. The flange caps are available with a solid blank end, which can be machined with custom hole patterns, as well as with two and four M10 threaded holes for our cable penetrators. The flange caps do not require any screws, eliminating the need for stainless steel near the enclosures and preventing galvanic corrosion.

Flange cap with the locking cord installed.

Flange cap with the locking cord installed.

Four internal mounting holes make it easy to attach internal contents securely. This feature is used on the BlueROV2 to hold the electronics tray.

The end caps and flange caps are available individually here, but you can configure a complete watertight enclosure from the watertight enclosure configuration page.



Flange Caps:
  • 1 x Flange Cap (based on selection)
  • 2 x O-ring (-030 size)
  • 1 x 180mm PTFE Locking Cord with Locking Cord Handle
End Caps:
  • 1 x End Cap (based on selection)
  • 6 x M2x10 screws



Dome MaterialOptically Clear Cast Acylic
Retaining Ring MaterialPolycarbonate
Depth RatingDepth Rating in Product Selection Dropdown

Flat Acrylic Endcap

MaterialOptically Clear Cast Acylic
Depth RatingDepth Rating in Product Selection Dropdown

Flange Cap

Material6061-T6 Aluminum
Depth RatingDepth Rating in Product Selection Dropdown

2D Drawings


WTE2-LOCKING End Caps and Flange Caps (.pdf)

3D Models





WTE2-P-END-CAP-R2 (.zip)

WTE2-P-DOME-R1 (.zip)


Revision History

19 November 2019

  • R1 – Initial release


Watertight Enclosure (WTE) Assembly (New)

Learn how to quickly assemble a watertight enclosure!

Using the Vacuum Test Plug

Ensure the o-ring seals are good on our WTE with this quick test!


Blue Robotics Forums – Watertight Enclosures