Đầu chặn (track ends) cho Vernier Physics tracks

CHECK OUT THE VERSION 2!!!! 

I wasn't impressed with the standard Vernier Track ends, so I designed these! They are designed with a slot in the center, for a cart launcher, which I also designed. There is also an option to add the magnets that normally would go into the carts. Easier to remove the magnets than in the OEM models. 

You will need a ¼ square nut and a ¼ bolt, either ½ inch or ¾ inch.