These locs differ in size and installation technique. Sisterlocks are smaller and uniform locs created by making parts on the hair in a grid pattern. The locs are then locked by a special tool that prepares the hair for locking. Sisterlocks consist of more than 250 dreads. And also, trained sisterlock consultants do the installation. On the other hand, interlocks are larger and uniform locs created by freeform. The method involves grabbing the loc and pulling it through the base to continue locking the root. Like Sisterlocks, it uses a unique tool. But, interlock does not need a Sisterlock consultant to install.