By Liyi Signal Product Team | September 28, 2026
Selecting a warning light bar usually starts with length. That is the least informative starting point, because length is a consequence of the vehicle, not a specification of its own. The more useful approach is to start from the duty the vehicle performs, then match the series to it.
Liyi manufactures four long light bar series, all holding EU R65 approval. Each one exists because a different operating requirement could not be met as well by the others.
Five Questions Before You Compare Products
What is the vehicle’s duty cycle? Sustained highway patrol, urban response, or static work-zone operation each place different demands on a bar.
What roof geometry and mounting does the vehicle accept? Curvature, fixtures, and roof-loading limits determine what will sit correctly.
What is the electrical system? 12V or 24V — a wide-input design covering 9V to 30V removes the risk of specifying the wrong variant.
Is audible warning required as well as visual? Some applications need both in one unit; others do not.
What climate will the vehicle operate in? Temperature range and UV exposure drive material and design choices.
The Four Series
39000 Series — the broad-coverage, value option
The workhorse range. It holds R65 Class 1 and Class 2 dual approval, first obtained in 2012, together with R10 electromagnetic compatibility certification — dual approval that allows one range to serve both the base and higher intensity requirements.
Its defining feature for buyers is coverage of vehicle sizes: the 39000 series is available in 17 lengths, which makes it suitable for mixed fleets where a single platform has to fit passenger-derived and larger commercial vehicles.
Best suited to: fleets prioritising breadth of fitment, value, and a certified product with a long approval history.
61000 Series — combined visual and audible warning
The 61000 series adds an integrated high-pressure siren, with maximum sound pressure up to 120dB, so visual and audible warning come from a single certified unit rather than two separately sourced devices.
Consolidating has practical consequences: one installation, one document set, one change notification process, and one point of accountability when something needs servicing.
Best suited to: emergency response vehicles where audible warning is required alongside the light bar.
62000 Series — enhanced weather resistance
Where the 39000 series prioritises fitment coverage, the 61000 series prioritises resistance to the environment. The body is upgraded to aluminium alloy, and the series is specified for operation from -40°C to +50°C.
Aluminium bodies are also rated to withstand 60kg of direct pressure without deformation — relevant where bars are leaned on during maintenance or exposed to mechanical loading.
The 62000 series supports both bracket fixing and magnetic attachment, which matters for vehicles that are rotated between duties or where permanent installation is not appropriate.
Best suited to: vehicles operating in demanding climates or on rough surfaces, and fleets that need flexible mounting.
63000 Series — ultra-slim, high-speed profile
The 63000 series stands 95mm high. That profile was chosen specifically to reduce wind resistance and frontal area for vehicles operating at sustained highway speed, where drag and cabin noise carry a real cost.
Reducing height does not reduce the optical requirement. The series retains full R65 approval, and — like the 62000 — it offers integrated siren capability for applications that need audible warning.
Best suited to: high-speed patrol and response vehicles where aerodynamic profile and cabin noise matter.
Length, Mounting, and Colours
Length selection should follow the vehicle: bars are typically chosen so the lit surface spans the roof width without overhanging beyond the vehicle’s outline. The 39000 series’ 17 lengths and the 500–2200mm coverage of the 61000, 62000, and 63000 series between them address most passenger-derived and commercial emergency vehicle platforms.
All series support bracket fixing and magnetic attachment, and LED colours are customizable in red, blue, yellow, and white.
One caution on colour: which colours may be displayed, and in what combinations, is set by national regulations, not by the manufacturer. Confirm the permitted configuration for the registration market before specifying.
Matching Series to Vehicle
Mixed fleet, broad fitment, value focus → 39000 series
Harsh climate or rough-road duty → 62000 series
Response vehicles needing siren and light together → 61000 series
High-speed highway patrol → 63000 series
Where a fleet contains several vehicle types, splitting the specification by duty usually produces better results than applying one series across the whole fleet.
FAQ
Q: Are all four series certified to ECE R65?
A: Yes. The 39000, 61000, 62000, and 63000 series all hold EU R65 approval. The 39000 series holds Class 1 and Class 2 dual approval, obtained in 2012, and passed R10 electromagnetic compatibility certification at the same time.
Q: Can a light bar with an integrated siren be installed on any vehicle?
A: Installation depends on the vehicle’s electrical system and roof configuration rather than on the bar’s capabilities. Both the 62000 and 63000 series support bracket and magnetic mounting, and the wide 9–30V input range suits 12V and 24V systems.
Q: How do I choose between the 61000 and 63000 series?
A: The deciding question is speed. A vehicle operating at sustained highway speed benefits from the 63000’s 95mm low-profile design. A vehicle working in harsh conditions at lower speeds benefits more from the 61000’s focus on weather resistance and structural durability.
Before you specify a series, define the duty cycle, confirm the mounting and electrical requirements, and check the required R65 class. LIYI provides specifications and approvals for all four series on request.
EN