The York Economy Rubber weight training discs are made with recycled rubber, providing excellent flooring protection & can be used with any York Olympic bar. All plates come as standard, with a 2” steel centre sleeve These plates do not have any casting inside, just solid rubber They are ideal for teaching Olympic movements such as snatch & clean & Jerk, as they are made to the correct Olympic diameter of 45cm These plates are perfect for using on the York lifting platforms as they will protect the platform should a failed lift occur & the bar needs to be dropped. Note: Please be aware these plates will have a strong rubber smell for a few weeks due to the manufacture process, this will however reduce over time. These plates are also a different construction (materials & process) than the previous rubber plates sold by us, which have the white lettering & USA on the plate, & as a result come with a 6 month warranty on manufacture defects.