Neewer Metal 13-21-31mm AF Auto Focus Macro Extension Tube Set for Canon DSLR Cameras Such as 7D Mark II,5D Mark II III,IV,1300D,1200D,1100D,750D,700D,650D,600D,550D,500D,100D,80D,70D,60D Lightweight design Material: Plastic Perfect coupling with TTL.AE Metering Use Individually or Combined Lengths FOR tubes (mm): Tube #1: 13; Tube #2: 21; Tube #3: 31