Gas mask connection hose — flexible 40 mm threaded trachea

This connecting hose is a corrugated flexible tube (“trachea” type) fitted at each end with a standard threaded metal connector, generally the 40 mm thread (EN 148-1 / GOST standard) found on most gas masks and filters. In consensual rubber/fetish BDSM use, it serves to extend or reposition a gas mask's connection: you can attach a filter, a valve, a rebreathing bag, another mask or an airflow-control device, in order to build breath play between partners.

Within a scene, its appeal lies in modulating breathing and in the psychological weight of the gas mask. The hose lets you move the air intake away, place it in a partner's hands, or link two people together. The experience being sought is one of breath made conscious, slowed, framed — a sensory experience about building trust and letting go, never about depriving anyone of air.

The prevention side is absolutely central here, because anything involving breathing is among the highest-risk practices in BDSM. The non-negotiable principle is simple: air must always be able to circulate freely. A hose, a mask or a filter must never be used to block, heavily restrict or cut off the air supply. Breath restriction (making breathing “laboured” in a controlled way) is already an advanced practice demanding experience, caution and supervision; occlusion (cutting off air) must never be practised, because loss of consciousness through lack of oxygen can happen without warning and lead to serious consequences, up to and including death.

Several concrete points of vigilance apply. Check that the circuit cannot end up completely closed (no valve or plug that cuts off air with no way out), and keep an emergency air intake that is easy to open. Monitor the masked person continuously: lip colour, the rhythm and ease of their breathing, level of consciousness, responses to questions. Since the gas mask covers the face, make sure too that it can be removed within seconds — straps that loosen quickly, no locking around the skull without a means of immediate release. Agree a safety code usable even while masked: a non-verbal signal (a gesture, an object to drop, an agreed tap) since speech is muffled.

The supervision rule is stricter here: never leave someone alone while they are wearing a mask connected to a breathing circuit, not even for a moment. Keep the duration limited, stay alert to the slightest sign of discomfort, dizziness, tingling or confusion, and stop immediately at the first doubt. Consent is discussed beforehand, checked during, and respected at every moment.

A word on filters: if a gas-mask filter is connected — especially an old one from military surplus — it may be out of date, clogged, or contain aged filtering materials that are potentially irritating or dangerous to inhale. For fetish use, many therefore prefer to play with no active filter, or with a simple part ensuring a clean, clear air passage, rather than with an old filter of uncertain composition.

As for care, the hose should be cleaned in lukewarm soapy water, rinsed and dried completely on the inside before storage to prevent mould and odours. Check the condition of the bellows (cracks, crazing) and of the metal threads regularly — their seal and soundness are part of what keeps the whole assembly working properly.