Aluminum End Cap with 18 Holes (4″ Series)


This 18-hole aluminum end cap is compatible with the 4″ Series Watertight Enclosure. It can be used with the BlueROV2 and adds four additional cable penetrations for more expandability!

In stock

HS Code: 3923.50.00

Product Description

This 18-hole aluminum end cap is compatible with the Watertight Enclosure for ROV/AUV (4″ Series) and the BlueROV2.

Unlike most of our other end caps, which have 10 mm through-holes for each penetrator, this one has a mixture of threaded and through-holes to allow more penetrations to be packed in. The outer eleven holes are threaded with standard M10 threads. The inner seven holes are through-holes just like our other end caps. All of the holes are compatible with all of our M10 penetrators.

One of the holes, noted in the drawing on the Learn tab, is spaced further from the others to allow it to be drilled and tapped for a 7/16″-20 thread, which enables the use of many typical subsea connectors in that hole. If you’d like to use this feature, you’ll have to drill and tap that hole yourself.

This end cap is compatible with the BlueROV2 and provides a lot of expansion room. Please see the Learn tab for a recommended configuration of cable penetrators for use on the BlueROV2.


  • 1 x Aluminum End Cap with 18 holes (11 with M10 threading and 7 through-holes)
  • 6 x M3x12 screws


MaterialAluminum 6061-T6
Surface FinishHard Anodized Black
Weight in Air172 g 0.38 lb
Depth Rating 400 m 1312 ft
**Final depth rating TBD upon further testing**

2D Drawings

** This hole can be tapped with 7/16″-20 threading for a wet-mateable connector

3D Models

WTE4-M-END-CAP-18-HOLE-R2 (.zip)

Revision History

13 November 2018

  • R2 – Initial Release

BlueROV2 Heavy Suggested Penetrator Organization

Note: For an easier installation process, begin with penetrator accessories that don’t have cables, then working from the middle to the outer holes.

Tapping for a Subsea Connector

  1. Drill out existing M10 hole with a 25/64″ or 10mm bit.
  2. Thread the hole using a 7/16″-20 tap.


Watertight Enclosure (WTE) Assembly

Learn the basics of assembling a Watertight Enclosure (WTE)!

Using the Vacuum Test Plug

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


Blue Robotics Forums – Watertight Enclosures