1.Top Tightening Toilet Seat Bolts and Screws with 3 Various Solution. Feel Free To Choose a Best Solution as Your Installation Need, Easy installation. 2.First Solution: 2 PCS (1Set) Black Expanding Rubber (with Two Expandable Ball) with 7cm Lenght Bolt and Stainless Steel Gasket. 3 .Second Solution: 2PCS White Screw with Solid Brass Screw Inside with 5cm Lenght Bolt Fix Blind Hole. 4.Third Solution: 2PCS Downlock Screw Nut with Brass Screw Inside for Downlock as You Need. 5.It Is Suitable for Universal Toilet seat. Can be Installed on Most TOTO, Kohler, American Standard Toilets and Others.