Removable Snap-In Ratcheting Strain Reliefs Heyco Removable Snap-In Ratcheting Strain Reliefs self-lock onto the cable and are designed for Round and 'Double D' mounting holes. A wire locking ratchet allows for wire ranging from 0.115' to 0.75' (2.9mm to 19.1mm) and can be used for multiple flat or round cables. The Heyco Removable Snap-In Ratcheting Strain Reliefs are easily installed with fingertip pressure into a standard round or 'Double D' hole. Ratcheting strain reliefs can be easily removed by inserting standard snap ring pliers with .040' tips into the two holes on the part and spreading part open.