Waggler Floats.

Of all the items of tackle you can buy, which float to choose is probably the most difficult choice you'll have to make. There are literally thousands of different shapes, weights, and colours of fishing floats. 
To start with, you only need be concerned with a couple of types of floats, commonly known as 'Wagglers'. 

For heavier baits like meat, corn, and large pellets, use a straight Waggler with a thicker tip.

For more sensitivity and for lighter baits, use the thinner Insert Waggler.

Which colour you use is up to you, most anglers go for red tips. But it's always handy to have a few yellow tipped Wagglers for certain conditions.