Replacement autovent power tube for Bayliss MK7 openers. These are our “Superior” type tubes, which open at slightly higher temperatures than the standard bayliss tubes, and slightly lower temperatures than the orchid tubes. Adjustable beginning opening temperature of 65 – 75°F. Fully open at 20° higher. Comes with instructions and replacement “star” washer. Free Shipping. If you are interested in purchasing more than 5 of these, we suggest you contact us via phone or email to discuss shipping options.