These are rubber stoppers to prevent chair casters from moving. 4 pieces per set. All contents are shown in the second photo. They will be sent in a paper envelope. ※ The caster itself shown in the first photo is not included. I will ignore any price negotiations. Thank you for your understanding. Manufacturer: aamono Compatible size: Compatible with casters up to approximately 5cm in diameter (※ Varies depending on the shape) Thank you for viewing.