Roller Derby 826G Inline Skate Brake Stopper 2 Roller Derby 673G inline skate heel stopper/brake parts Grey stopper approved for use in most skating rinks Attaching screw goes through the side. Fits Roller Derby models: I238&I338 AERIAL, I221&I321 EUROPA, I224&I324 FORMULA Z7, I121 SENSOR XT, I228&I328 SR 700, I232&I332 Z550, I506 LAUNCH, I257 MALIBU, I507 TRAC 5000, I509&I559 VEGA