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Replacement for FireAngel SO-601 9V Optical Smoke Alarm - UltraFire ULLS10

4.8 out of 5 stars
£22.43 inc VAT
£18.69 ex VAT
Product Overview

The FireAngel SO-601 optical smoke alarm with toast proof sensing technology, operated by a 9V alkaline battery is less prone to sounding falsely due to cooking fumes. As the SO-601 is now discontinued, an adaptor plate designed to fit your existing baseplate has been manufactured. The adaptor will accommodate the UltraFire ULLS10 optical smoke alarm with no need to drill new holes on your ceiling.

The UltraFire ULLS10 is powered by a sealed 10 year battery that will not need replacing for the full lifespan of the alarm, and will activate automatically when installed. The adaptor plate simply twists onto your existing SO-601 base plate and provides an ideal and quick solution for the replacement of this alarm. Like the FireAngel SO-601, the UltraFire ULLS10 optical smoke alarm features an end of life warning which can be silenced for up to 10 hours should it occur during the night, and for additional peace of mind it is backed with a 10 year manufacturer's warranty.

  • FREE delivery
  • Suitable for installations in hallways, landings, living areas and bedrooms
  • Battery: 10 year sealed lithium battery
  • Warranty: 10 year manufacturer's warranty
  • Includes UltraFire Adaptor Plate designed to easily replace old FireAngel SO-601 alarms with the UltraFire ULLS10
    • Removes the requirement to drill additional holes or redecorate when replacing alarms
    • Fits onto existing FireAngel SO-601 base plates
    • Simple twist-on installation
  • Combined test and silence button, almost the whole face of the alarm
  • End of life / low battery warning chirps can be silenced up to 10 hours
  • Automatic activation and deactivation when attached and removed from the base plate
  • Suitable for installations BS 5839-6: 2019 Grade F1
  • CE marked, UKCA marked, and Kitmarked to BS EN 14604: 2005

Please Note: The UFFASTAP adaptor plate is used for mounting the ULLS10 smoke alarm to an existing FireAngel SO-601 base plate – do not use the standard base plate included in the box with the ULLS10 smoke alarm as well. The standard base plate is only intended for use on its own to directly mount an ULLS10 to the ceiling


This adaptor plate has been designed for use with an UltraFire 10 year alarm in order to help customers replace popular, discontinued FireAngel alarms as easily as possible. By utilising this adaptor plate and the existing base plate on your ceiling, there is no need for any tools, for drilling new holes, or to cover up marks from the previous installation.

In order to replace your old FireAngel alarm, please follow these steps:

  1. Rotate the old FireAngel alarm anti-clockwise to remove it from the base plate
  2. Remove your new UltraFire alarm from the box and discard the standard base plate supplied with it
  3. Rotate the UltraFire alarm clockwise onto the adaptor plate until you hear a click
  4. Test the UltraFire alarm as per the instruction manual to confirm it is working properly before fitting it to the ceiling
  5. Rotate the UltraFire alarm and adaptor plate clockwise onto the old FireAngel base plate that is still attached to the ceiling
    • The outside edge of the adaptor should travel approximately 3cm
Technical Data
Product Code FASO601
Alternative Product Codes ST-622, ST-622T, ST-622Q, ST-622R, s601, ST622, SO601, ULLS10
Battery Type

10 Year Sealed Lithium



Dimensions (HxDia)

Adaptor Plate: 3.8 x 117mm

ULLS10 Optical Smoke Alarm: 34 x 84mm

Operating Temperature

5°C to 30°C

Relative Humidity

< 85%

Sound Output



10 Years

Weight 0.21kg
Product Datasheets
FAQs (1)
Q. Can a smoke alarm be fitted with a sticky adhesive pad in a let property?

The sticky pad is suitable for all battery operated smoke alarms. However, we cannot judge if battery alarms are suitable for your let property, as let properties usually require mains powered alarms. There is some advice to this in the governments guides to fire risk assessments. Also see the LACoRS guide for let properties.

Pricing & Availability

Model Stock Price
Product Code: FASO601 Stock Level:
More than 20 in stock Expected dispatch: Tomorrow

£22.43 inc VAT

£18.69 ex VAT

Delivery Options

The following delivery options are available on this product.

Free Economy Delivery

Free of Charge - Orders will be delivered in 5-7 working days with Evri

Standard Delivery

£3.19 inc VAT - Orders will be delivered in 2-3 working days with Evri

Next Working Day Delivery

£6.19 inc VAT - Orders will be delivered the next working day with Evri

For dispatch today order within

Excellent Warranty

This product is supplied with a 10 year manufacturers warranty as standard

Customer Reviews

92 customers have given this product an overall rating of 4.8 out of 5

Reviews by real customers

All of our product reviews are written by real customers that have purchased this product from us and are published without modification.

Rating: 4 / 5 Stars

Reviewed by: T M

Practical and does the job

Published on: 25th May 2024

Rating: 5 / 5 Stars

Reviewed by: I C

Easy to fit and use replacement alarm. A very good idea to reuse existing fittings, works ell.

Published on: 12th December 2023

Rating: 5 / 5 Stars

Reviewed by: J H

Fitted on to the back plate of our old alarm in the caravan, as described

Published on: 12th October 2023

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