what do you clean mannikins with?

I use any kind of cleaning wipe. Alcohol wipes are fine.

Is feedback audio and visual

Yes, these particular manikins do provide audio and visual feedback. These PRESTAN Manikins feature a clicking mechanism that indicates correct compression depth to students and instructors with an audible CLICK. The clicker itself is located in the chest cavity of the Adult and Infant Manikins. When students are practicing CPR compressions on these manikins, not only will they see when they have reached and are maintaining the minimum recommended speed of 100 cpm, they will also see when they exceed the upper limit of 120 cpm - the yellow monitor light will flash to let them know! How the CPR Rate Monitor Works: 1. Begin compressions on the Prestan Professional Manikin 2. When you reach the correct compression depth of 2-2.4", you will hear an audible CLICK to confirm 3. The clicker sends a signal to your CPR Rate Monitor with each compression and the CPR Rate Monitor instantly and continuously responds to your speed with color-coded LED lighting for invaluable feedback!

Is everything in this set the same as the set of 4?

This pack provides all of the essentials to begin a CPR training career in one affordable collection featuring: -Two adult Prestan Professional Series manikins compliant with AHA guidelines -Two infant Prestan Professional Series manikins compliant with AHA guidelines -Two Prestan UltraTrainer AED training devices -Two Adult ManiVests and Two Infant ManiBibs -Two CPR Kneeling Mats -Starter 20-pack adult sized lung bags and 20-pack infant sized lung bags -Specially designed carry case So, all of the CPR material in this Take2 Kit is the same, however the bag is a different size from the K404M.