SLS MK IV bail out system


The Divex secondary life support (SLS) MK IV is the predecessor to JFD's new COBRA rebreather and has now been discontinued.

JFD will support units in the field with spares and service for a period of two years, (end 2019) after which time any remaining users will be encouraged to upgrade to new COBRA sets.

COBRA (Compact Bailout Rebreather Apparatus) incorporates many technical advances and is available at a reduced target price.


The SLS MK IV is an emergency breathing apparatus intended for use in the event of a fundamental failure of a diver’s primary life support umbilical enhancing diver safety even in the extreme depths of the world's most hostile environments. Operating on a semi-closed circuit rebreather principle independent from the primary system, the SLS MK IV provides over 13 minutes of warm breathing gas at depths of 400 metres. 

SLS MK IV - backpack SLS MK IV - side view SLS MK IV - front view SLS MK IV - front view SLS MK IV - diver SLS MK IV system SLS MK IV - back view

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SLS Backpack - Prod.jpg

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SLS Diver Side - Prod.jpg

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SLS Diver 1 - Prod.jpg

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SLS Diver front - Prod.jpg

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SLS Diver 3 - Prod.jpg

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SLS System 2 - Prod.jpg

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SLS back view - Prod.jpg


SLS backpack  
Width 12.45" (316mm)
Depth 5.67" (144mm)
Height 20.29" (515mm)
Height in air 50.6lbs (23kgs)
Height in water

7.7lbs (3.5kgs)

SLS helmet

Weight in air


Weight in water









Depth (msw) Cylinder charging pressure bar (max)
(at the surface)
Duration (minutes)
50 300 56
100 300 37
150 300 28
200 300 22
250 300 19.5
300 300 17.5
350 300 16
400 300 13.5
Item Order code
SLS MKIV System c/w Ultrajewel 601 reclaim helmet A44740
SLS backpack and helmet interface to retrofit to customer’s 17C reclaim helmet A44770
SLS MK V Backpack Upgrade kit B44750-UPGRADE
SLS system tool and instrumentation set C10203
Spares kit C10202
Hygiene flushing kit C10205



Type Document Download
Datasheet SLS MK IV Deep Diving Bail Out System

DE-MDS-596 R2

Drawing SLS MK IV system overall assembly

P1939196S1 R1

Drawing SLS system tools and instruments set

P1939204S1 R5

Manual SLS MK IV system backpack operation and maintenance (Part number: B44771)

P1939-OM-131 R12

Manual SLS MK IV system helmet operation and maintenance  (Part number: A44772)

P1939-OM-112 R10



The SLS diver familiarisation and SLS servicing courses will ensure participants have the expertise required to correctly operate and maintain the SLS MKII bail out system.

SLS diver familiarisation course duration: 1 day
SLS servicing course duration: 3 days

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