This Motta coffee leveler can be used with any 58mm portafilter.
It is is height adjustable  screw off top anti-clockwise to make leveller deeper.
 
It is made in Italy to high standards and is heavy weighted at 400 grams. 

Before you tamp the coffee - using this leveler will  allow you to obtain the correct density, which will minimize channeling and increasing coffee extraction, ensuring greater consistency in the amount of espresso served.