Specifications Type: HGR20 Slide Rail Material: Gcr15 Steel Rail Shaft Length: 39.3 in / 100 cm Nuts: BF12 / BK12 Nuts Fixing Screw Hole Size: M4 x 16 mm Static Load Ratings: 25.31 Allowable Static Torque: 0.17 KN.m Performance: Smooth Motion, Low Noise Net Weight: 24 lbs / 11 kg Block Dimensions(L x W x H): 2.8 x 1.6 x 1.3 in / 7.3 x 4.2 x 3.4 cm Package Content 2 x HGR20-1000 mm Linear Guide Rails 4 x Slide Blocks 1 x RM1605-1000 mm Ballscrew 1 x Ball Nut 1 x BF12 / BK12 Nut 1 x Plum Coupling