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How to use a Bosch cross line laser

Updated: 22 October 2026

You have unboxed a Quigo, a UniversalLevel, or a GLL or GCL, and the line is blinking on the wall. This is how to use a Bosch cross line laser in the nine-listing set on our [Bosch cross line laser comparison](/hub/measuring-equipment/bosch-cross-line-laser): put it on a firm base, unlock it, wait until the line is steady, mark the centre, and raise the support if the mark is higher than the tool. The Products Compared editorial team used the Quigo Green manual, amazon.co.uk review notes, and UKHSA and HSE advice on class 2 lasers. We did not run a lab test. A qualifying purchase can earn us a commission at no extra cost to you.

You have unboxed a Quigo, a UniversalLevel, or a GLL or GCL, and the line is blinking on the wall.

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Bosch Professional Bosch Professional GCL 2-15

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Bosch Professional Bosch Professional GCL 2-15
9.2/10about £119.99
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Bosch Professional Bosch Professional GLL 2-10

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Bosch Professional Bosch Professional GLL 2-10
9.0/10about £89.95
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Bosch Bosch Quigo 06036635Z0 with MM 2

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Bosch Bosch Quigo 06036635Z0 with MM 2
8.4/10about £55.14
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On this page
  1. 1.Put it down and unlock it
  2. 2.Wait until the line stops flashing
  3. 3.Mark the centre, then raise the support
  4. 4.Diagonals and when to stop

Put it down and unlock it

These tools level themselves with a pendulum. A rattle when a Quigo is switched off is described in reviews of B0CGXSPRWP as play in that pendulum, not as a broken housing. Unlock on the surface you mean to use, not in your hand. The Quigo Green manual asks for a firm base, with the tripod thread facing down if the tool is on its mount. A 1/4 inch thread will take a camera tripod if the included stand is the wrong height. The GLL 2-10 also has a 5/8 inch thread on Bosch's own page. The amazon.co.uk bullets do not name that thread. Cells in this set are AAA or AA.

Wait until the line stops flashing

A flashing line means the tool is outside self-levelling. On the Quigo Green manual, the lines stop flashing when the tool has levelled, and a slow flash means the base is more than about ±4° off, or you are holding the cube. GLL 2-10 reviews say the lines flash outside self-levelling, and one review says that model switches off after about 2 minutes without a button press. Do not copy that 2-minute remark onto a Quigo. There is no second-count in the Quigo Green page we used, so about five seconds would be a guess. Put the tool down, take your hand off it, and wait until the line is steady before you mark.
Bosch Professional Bosch Professional GCL 2-15

Testsieger

Bosch Professional Bosch Professional GCL 2-15
9.2/10about £119.99
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Mark the centre, then raise the support

The Quigo Green working-advice page tells you to mark the centre only. Pencil the middle of the glow and ignore the fuzzy rim. If you mark the top edge at one end of a shelf and the bottom edge at the other, the shelf will lean even though the tool was level. The included tripods are about 1.1 m. You do not reach a ceiling by tipping a self-levelled head upward. Raise the support, or measure up from a lower steady line with a tape. The GCL 2-15's RM 1 has no height adjustment once it is hung from a nail. Which stand is in which kit is on the Bosch cross line laser buying guide.

Diagonals and when to stop

A diagonal is a slope, useful for a stair string or a feature batten, and it is not a level line. The UniversalLevel 360 has a locked slope mode: you lock the pendulum, set the angle, and the beam is no longer self-levelled. A flashing Quigo on a tilted book is outside ±4°, and the cross is not a promise of square. Stop if the line will not settle on a firm, nearly level base, and return the tool. Do not invent a calibration routine these pages do not give you. The Consumer Rights Act 2015 is the route when goods are not of satisfactory quality. Class 2 is visible light. UKHSA says a short glance is covered by looking away, and staring is hazardous. Outdoor daylight is on Bosch Quigo green or red.

Common questions

Why is the line on my Bosch cross line laser flashing?
A flashing line means the tool has not self-levelled. On the Quigo Green manual, a slow flash means the base is more than about ±4° out, or you are holding the cube. The cross is then not necessarily square. GLL 2-10 reviews describe the same idea: the lines flash outside the self-levelling range. Wait until the line is steady before you mark.
Where on the line do I put the pencil?
Put the pencil on the centre of the line. The beam widens with distance, so the bright rim and the middle are not the same height. The Quigo Green working advice says to mark the centre only. If you use the top edge at one end of a 2 m shelf and the bottom edge at the other, the shelf will slope even though the tool had levelled.
How do I get a mark above a 1.1 m tripod?
The 1.1 m tripods, and the Quigo Green stand rated to 110 cm, leave the line at about tool height. Measure up from that steady line with a tape, or put the tool on a taller support such as a camera tripod on the 1/4 inch thread. Do not tilt the head toward the ceiling while it is still in self-level mode.
How do I set a diagonal without pretending it is level?
Use a locked slope mode when the tool has one. The UniversalLevel 360 listings describe a locked mode for diagonal lines. The pendulum is then fixed, and the beam is a slope you chose, not a level. A flashing line on a tilted Quigo is the tool failing to self-level, not a diagonal setting.
What should I do if it still will not settle?
If the line keeps flashing on a firm base that is within a few degrees of level, stop and return the tool. These pages do not describe a home calibration. For a set-out, a specified fall, or work at height where the beam could dazzle you on a ladder, use a receiver or a rotary meant for that job, or bring in someone who sets out buildings.

Related pages

Best Bosch cross line laser

Bosch cross line laser

Bosch cross line laser buying guide: shape, then spec

Bosch Quigo green or red: an indoor brightness check

Bosch Quigo vs GLL 2-10: cube or Professional tool

Sources

Public UK sources and Bosch UK pages from the research digest, last checked on 20 October 2026. Shelf prices and star lines are the amazon.co.uk figures captured with these nine listings. Bosch's own shelf prices sit beside them and are not the scores.

  1. UKHSA: laser radiation safety advice (retrieved 20 October 2026)
  2. HSE: lasers (retrieved 20 October 2026)
  3. Bosch DIY: Quigo manual (en-GB) (retrieved 20 October 2026)
  4. Bosch DIY: cross line lasers (retrieved 20 October 2026)
  5. Bosch DIY: Quigo Green (retrieved 20 October 2026)
  6. Bosch DIY: UniversalLevel 360 set (retrieved 20 October 2026)
  7. Bosch Professional: GLL 2-10 (retrieved 20 October 2026)
  8. Bosch Professional: combi lasers (retrieved 20 October 2026)