The original FitLock

https://www.youtube.com/watch?v=QdWyfm0sNGg

 

01 - FitLock Hard (FLH)

Fitlock

01 - FitLock Hard (FLH)

$ 4

02 - FitLock Soft (FLS)

Fitlock

02 - FitLock Soft (FLS)

$ 4