Apeks Low Pressure Rubber Hoses All LP hoses and Inflator hoses are manufactured at the Apeks factory. Lightweight flexible hoses withstand a burst pressure more than twice that of traditional hoses. The typical standard hose length for Primary second stage is 75cm, but pleae note that it might vary from manufacturer to manufacturer and potentially even between sizes. Most regulators use two different fittings, one for low pressure supplied to the second stage and another for high pressure for contents gauges and transmitters, which prevents the wrong hose being inserted into the wrong port. Generally, low pressure uses a 3/8\" threaded hose and high pressure uses a 7/16\" hose. However, some manufacturers use other sizes (most commonly a 1/2\" port) for the low pressure side.  Features: Genuine Apeks hoses Rubber) and we will send you a costing Made in-house at Apeks.   See length options and fittings Regulator First Stages that use 3/8\" UNF Low Pressure Ports All current Apeks All current Aqua Lung All Cressi All Dive Rite All Oceanic All Scubapro All Seac Sub Mares 2S, 12S & 52 first Stages Regulator First Stages that use a 1/2\" UNF Low Pressure Ports Some older Apeks Mares 22 first Stage Safe Second Stages These units use a different quick disconnect to the one used on a normal inflator but the hose itself is the same as a regulator hose with the addition of an adapter on the end. There are a couple of different adapters so make sure you get the right one if you need to replace the hose / adapter. For the Apeks Octo Plus, SeaQuest AirSource (including 1, 2 and AirSource3 QD), Zeagle Octo-Plus, Aqualung Air Mic, Mares Air Control, Beauchat Venturi, US Divers Air Mic, Oceanic Air XS, Aeris AirLink and compatible BCDs. For the Scubapro Air II, Tusa Duo-Air, Sherwood Gemini, DiveRite RiteSource, H2Odyssea Inflator plus, Atomic Aquatics SS1 or Zeagle Octo-Z Breathable and compatible BCDs.