What is the Inspire Fitness Leg Attachment? The Inspire Fitness Leg Attachment is just one of the upgrades available for the SCS or FID benches. Allowing for exercises such as hamstring curls & quadriceps extensions by placing a weight on the allotted arm the Leg Attachment add on isolates the area & for focused resistance. The heavy duty steel attachment is robust & hard wearing, designed for sustained use & a maximum user weight of 273kg.