This manual wrench is crafted from premium - grade alloy steel. The robust material not only provides exceptional strength but also ensures resistance to wear and corrosion. Whether you're dealing with tough nuts and bolts in a workshop or outdoor projects, the wrench can withstand heavy - duty use without deformation, guaranteeing long - term performance. Comes with 16mm (5/8") and 21mm (13/16") sockets to fit most spark plugs (please confirm spark plug size before purchasing) Flexible head allows access to tight areas. Ideal for use in tight access areas T-handle for increased leverage Internal plastic sleeve prevents damage to spark plugs Engineered with user comfort in mind, the wrench features an ergonomic handle. The shape is designed to fit the hand perfectly, reducing hand fatigue even during extended use. The handle also has a non - slip surface, providing a secure grip in various working conditions, be it oily, wet, or dry, ensuring safe and efficient operation. It is designed to offer a precise fit for a wide range of nuts and bolts. The jaws of the wrench are accurately machined to match standard fastener sizes, allowing for a snug and secure hold. This precision ensures that you can apply maximum torque without slipping, making it easier to loosen or tighten stubborn fasteners, saving you time and effort.