Starburst: the starburst response system is a set of grooves in a star-type shape that outline the yoyo’s center.
K-pad: A K-pad is very similar to silicone pads but is used for more unresponsive play
Silicone pads: silicone pads or just simply, “silicone” is a rubber-type material that grips on string very easily. Silicone is used a lot in an “unresponsive yoyo”.
O-ring: An o-ring is made out of rubber and is similar to silicone pads. An o-ring sits in the same place silicone does but is convex (the opposite of concave). it outlines the center of a yoyo in a circle.
String: There is currently only one yoyo using the string response system, which is the loop 720. The string response is a response system that outlines the center of a yoyo in a circle, like silicone and o-rings, but the material is yoyo string.
Friction Stickers: Friction stickers are mainly used by duncan as a response system. It is commonly referred to as a “cheap way of response” because they are not very long-lasting and are inexpensive to buy. They use a stickey surface on top of a very thin sheet of canvas. It outlines the center of the yoyo, like silicone and o-rings.
Foam stickers; Foam stickers are exactly the same as friction stickers but are made out of a squishy foam material.
None: There are only a couple of yoyos that don’t even use a response system, mainly offstring yoyos. One example is the new YYJ Fiesta.
@ jetboy: The fiesta actually has a response. It is called a tapered gap and it is where the gap is small enough that the string can grab itself and wind.