This is the smallest diameter vacuum hose I could find. Used it to hook up sensors to my engine's air intakes. Ideal for connecting to very small NXP surface mount pressure transmitters. It is very flexible but does not kink.
π Silicone Throttle Body Hose for Subaru WRX 2008-2014 - Mishimoto MMHOSE-SUB-ITBBK (Black)
9 Review
π K&N Cold Air Intake Kit: Boost Horsepower on 2015-2016 Ford F150 Turbo Ecoboost, 3.5L V6, 63-2592
9 Review
π§ Enhance Performance with Spectre 8711 Vacuum Sensor Adapter Kit
9 Review
π Enhance Your Vehicle's Performance with the Airaid 200-919 M.I.T. Modular Intake Tube.
9 Review