The MR-R4+ is a locking block assembly designed for M2 connector applications, providing secure mechanical fastening and alignment for connector mating. The assembly comprises a zinc die-cast locking block with nickel plating, an M2.6×8 nickel-plated steel screw, and an M2.6 nickel-plated steel spring washer. Dimensional specifications include mounting hole spacing of 4.8±0.3 mm and 7.6±0.3 mm, with overall dimensions of 8.4±0.3 mm and 9.8±0.3 mm. This locking block is compatible with MR-series connectors (M, MW, MD2 variants) and MRP-series connectors, making it suitable for automotive and industrial connector applications requiring reliable mechanical retention and RoHS compliance.