Josh11213 is correct, it is internal on a per detent basis that repel the piston away from the cap in the forward position. We make and sell single detents for markers that only require one detent. There are performance benefits to using magnets vs a spring:
Springs function in a linear motion over distance traveled. The patent pending Kila V2's with magnetic suspension work with a non-linear function in which force is magnified over distance traveled. What that means to you is less force on the paintball upon intial contact with the detent piston, but more force at the end of the piston stroke for a fast return, less wear, and greater reliability.
The adjustability of force (adding or subtracting magnets) is great if you need more or less force depending on the hopper you are using (force-fed or gravity), and other variables like the weather(cold weather = more fragile paint), or overall quality of paint.
The low friction rebuildable delrin piston can not be blown out of it's casing like a typical spring-loaded ball detent can. Internal parts can be adjusted, cleaned or replaced without having to purchase a complete new detent.
Springs tend to rust, weaken, and bind with dirt occasionally. No rusting, weakening or binding with the V2, just a "pocket" of opposing force we call magnetic suspension. I hope some of this info answers your questions!
Questions, comments, or how to earn yourself a free Kila V2 magnetic suspension detent today, send emails to firstname.lastname@example.org
Visit us on the web www.kilaproducts.com