50/50 is the oldest brand to make replaceable aggressive inline skate frames. It has been revived in recent years by Lawrence Ingraham. Follow him on his youtube pag http://youtube.com/backtoblading.

 

Size chart	S	M	L	XL
Width	50	55	60	65
Height	66	71	72	77

TIP: Measure an old shirt to know what you are used to.