Knitting needle end stoppers are a must-have in a knitters toolbox.  These  pushed  onto the end of your needles will prevent you from having a heart-stopping moment when you discover your stitches have fallen off, especially when doing lace work.  It's great for when your knitting is unattended or traveling.
These are plastic and come in 2 sizes.  These orange ones are for your tiny sized needles up to approx 3.5mm.
The blue stoppers  also listed are for needles 3.5mm on upwards.
They are sold in a pair of 2.  When you add 1 quantity to the cart, you will get 2 stoppers.