Wilkinson has a long established reputation of stellar quality at a great price point. These machine heads are no exception to that - these combine excellent manufacturing techniques and durable materials with an innovative new locking mechanism. The E-Z-Lock mechanism works to lock the string at the tuning peg by having two holes through the peg. The string is threaded through both holes to anchor it securely in place, preventing the normal slippage that can happen.
Locking machine heads are preferable due to their increased tuning stability compared to standard non-locking machine heads. Tuning instability can be caused by string binding at various points (machine heads, nuts, bridge, etc). Locking significantly reduces the binding at the machine head, making your instrument far less susceptible to tuning stability.