These rubbery black pegs fit into the hole on the bottom of a cart end cap to prevent the cart from rolling when placed on a flat surface such as a lab bench. When placed on a Vernier dynamics systems track, the peg protrudes into the central groove on the track and allows the cart to roll freely. Only one peg is needed per cart.
The peg is compatible with all green Vernier dynamics carts. It is compatible with most Vernier Fan Carts. Some models of the Fan Cart do not have a hole in the end cap for the peg. If you have such a fan cart, contact us and we can provide a replacement for your cart end cap that does have a hole.