FITS FOR: 2.28 inch/58mm thread diameter, suitable for 2.28 inch (58mm) tank hole. Dual flush function. Commonly used on brands: TOTO, American Standard, KOHLER, Twfords, Armitage Shanks, Geberi, Siamp, Wirquin, Cookr & Lewis.MATERIAL: The button spring is made of high quality 304 stainless steel wires, durable and elastic.SIZE: This is a two push button flush, so you can choose between full drain and half drain. And the total length of the torsion bar is 7.9 inch; you can cut or twist the length as you need to extend it. INSTRUCTIONS: 1. Unscrew the lock nut and put the button into the hole. (Full row and half row buttons should be consistent) 2. Check if the button stem is just touching the button. If it is too long, you can shorten it. If it is too short, you can rotate the knob shaft to adjust the required length and screw in the lock nut until it is tight. NOTE: Please check the size before purchasing due to different tank holes