How to fit a Protos helmet so it sits straight
Updated: 21 October 2026
The shell feels high or twisted, and the muffs miss your ears. Set the cradle before you decide the helmet is the wrong size. How to fit a Protos helmet uses a neck cradle with straps on both sides, three ride heights, and muffs that move from parked onto the ear. The steps come from the English manual. The [Protos forestry helmet comparison](/hub/protective-clothing/protos-forestry-helmet) is where the listings live. This page assumes the helmet is already yours. Peter F. set the steps on 19 October 2026.
The shell feels high or twisted, and the muffs miss your ears. Set the cradle before you decide the helmet is the wrong size.
The shell feels high or twisted, and the muffs miss your ears. Set the cradle before you decide the helmet is the wrong size. How to fit a Protos helmet uses a neck cradle with straps on both sides, three ride heights, and muffs that move from parked onto the ear. The steps come from the English manual. The Protos forestry helmet comparison is where the listings live. This page assumes the helmet is already yours. Peter F. set the steps on 19 October 2026.
Our top picks
| Badge | Product | Size on the listing | Closure named | Chin strap | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Pfanner Pfanner Protos Integral Arborist (black) | Not stated | Buckle | Strap channel | 7.2 | about £59.99 | View offer |
| Best value |  Protos Protos Integral Arborist (red/yellow) | One review: max of one size | Buckle | Named in reviews | 6.6 | about £227.70 | View offer |
| Alternative |  Protos Protos Integral Forest (F39 title) | 54–62 cm in the title | Buckle on a copied block | UK review: none in the box | 3.2 | about £59.99 | View offer |
On this page
Measure, then the neck cradle
Measure level around the widest part of your head, above the ears and across the forehead, before you touch the straps. The standard shell is 54–62 cm. Clips sold for about 52–60 cm and 56–64 cm will not invent a size outside that. The buying guide is the place for those parts.
Open the neck guard. Move both straps the same way, one notch at a time, until the cradle meets the back of the head. Close the guard so the fit is firm enough for a morning. This is a pair of straps, not a spinning ratchet. If the left strap sits two notches tighter than the right, the shell cocks and one muff misses the ear. Match the sides and check that the brim is level.
Ride height
The manual gives three ride-height positions. Use them to drop or lift the shell after the cradle length is even. Choose the position that keeps the brim out of your line of sight and the shell off the glasses you wear. Move one step, then look up as you would at a branch, and down as you would at the bar. If the shell rocks on your brow, the height is wrong even when the neck feels snug.
Check the straps again after you change height. A move on one side puts the twist back. A level brim with a leaking cup has failed the fit.
Muffs and visor
Move the muffs from the parked position down over the ears. A red Press tab releases the cup. The pad should meet the head all the way round, under the lobe and along the cheek. Set pressure with a coin on the regulator, arrows towards the front, until the cup seals and the pad does not ache after a few minutes.
The Health and Safety Executive treats a broken seal as a failure of hearing protection. Fit the muffs over the glasses you will wear. The mesh visor page is the EN 166 question. If a cup leaves its pivot, refit it once and retire that side if it leaves again.
When adjustment is the wrong job
Stop turning straps when the shell is cracked, the date has run out, or a blow has landed. UK shops say replace the shell every five years, with shorter intervals for the strap and the pads, and they do not share one start date with the manual. Read the stamp. Adjustment will not close a crack or restore a cradle that no longer holds a notch.
The manual’s wash is warm soapy water, with no solvent and no machine wash. If the sides will not match, or the foam has come away, replace the part or the shell. Reviews that mention loose foam are single reports.
Common questions
Where do I measure my head?
Run a tape level around the widest part of the head, above the ears and across the forehead. The standard Protos shell covers 54–62 cm. A small neck pad is sold for about 52–60 cm and a large neck closure for about 56–64 cm. Measure on the hair you will have under the helmet, and leave caps and hoods off the tape.
How do I set the neck cradle so the helmet sits straight?
Open the neck guard, move both straps the same number of steps, and close the guard so the fit is firm without pinching. The two sides have to match. A tighter left strap cocks the shell and pulls one muff off the ear. This cradle is a strap system. Look for a spinning dial and you will be adjusting the wrong helmet.
What are the three ride heights?
The manual provides three positions that lift or lower the shell after the cradle length is set. Pick the one that keeps the brim out of your sight line and keeps the shell off your glasses. Change a single step, then check that the left and right straps still agree. A shell that rocks on the brow is still at the wrong height.
How do I move the muffs from parked to on the ears?
Release the cup with the red Press tab and bring it down from the parked position onto the ear. The pad needs contact all the way round. Set the pressure with a coin on the regulator, following the arrows towards the front, until the cup seals and you can still wear it. Test that seal with the glasses you use for sawing.
What if one side is tighter than the other?
Loosen the tight side until it matches the other, then close the neck guard and look at the brim. Owners report that one strap can be stiff, so do this at a bench. If the sides will not equal, or a notch will not hold, stop. More force on the easy side makes the twist worse.
When should I stop and replace the helmet?
Replace the shell when it is cracked, when it has taken a heavy blow, or when the stamp puts it past the five years UK shops describe. Shorter intervals apply to the strap and the pads. Warm soapy water is for inspection. Solvent and a machine wash are outside the manual. If the muffs will not seal, change the part that failed.
Related pages
Sources
Public UK sources for helmet standards, hearing, mesh and PPE supply. Listing prices, stars and review counts are the amazon.co.uk figures stored in this set, not a live re-check. UK specialist shelves are the price check. Retrieved 19 October 2026.
- HSE — Chainsaw PPE (retrieved 19 October 2026)
- HSE — Aerial tree-work PPE (retrieved 19 October 2026)
- HSE — PPE product safety and supply (retrieved 19 October 2026)
- Control of Noise at Work Regulations 2005 (retrieved 19 October 2026)
- HSE — Hearing protection (retrieved 19 October 2026)
- Protos Integral UK — Arborist (retrieved 19 October 2026)
- Radmore & Tucker — Protos Integral Forest (retrieved 19 October 2026)
- Sorbus — Protos user manual (retrieved 19 October 2026)
- Gustharts — Protos Integral Forest (retrieved 19 October 2026)