This is not a genuine product, but it is compatible with Shimano's Uniglide old-type boss freewheels. The equivalent of the genuine tool model number TL-FW20 (TL-FF20). Outer diameter of the mountains: φ20.3-20.4 We will consider combined purchases or purchases with other products, so please leave a comment. Please understand that we will not negotiate a price reduction for this product alone. Please purchase without a comment unless you are in a hurry. (Shipping may be delayed by more than a week due to long holidays or business trips. If you are short on time, please be sure to contact us in advance to confirm the delivery date.)