What is the material used in Model 5 as Model 3 is using plastic?

“The Model Five device is made of Injection molded plastic, stainless steel, and elastomers.”

How often do the capsules need to be replaced?

Coravin Capsules power all Coravin Wine Preservation Systems, by pressurizing an unopened bottle of wine with Argon gas to pour a sip, a glass, or more. Each Coravin Capsule will allow you to pour approximately 15, 5 ounce glasses of wine (equivalent to 75 ounces). Capsule longevity will vary depending on how you use the Coravin System and how often and how much you pressurize each bottle.

Been reading issues with the needle breaking or bending. Any concern?

I have found that on occasion the needle comes loose from where it attaches / screws in, and if it has unscrewed itself and you use your Coravin, the needle can bend or potentially break while being pushed into a cork. I always check to make sure needle is secure before using -- no more problems.

What is the screw cap for?

The Coravin Screw Cap accessory provides wine lovers with the ability to pour and enjoy their favorite screw cap wines, expanding the possibilities of the Coravin Wine Preservation Opener by allowing people to pour and protect wines closed under screw cap for up to three months. Make sure to store your accessed bottles horizontally for optimal results.