1.PREMIUM STEEL MATERIAL - The linear motion slide rails are made of high-quality 55c steel; and blocks of GCr15 ball bearing steel and PA66, excellent non-conductor. The durable kit will endure through time. 2.EFFICIENT LINEAR GUIDING SYSTEM - The linear slide kit is a perfect combination of the main axle rail and blocks. With the smooth sliding of them, the transmission becomes so much easier. 3.EASE OF INSTALLATION - The linear bearing set has holes pre-drilled for ease of fixation. These several precise kits are easy to install, do the steps one by one carefully, though. 4.COMPLETE LINEAR RAIL KITS - The linear rail set will come with 2 pieces of 47.2""/1200 mm long HSR15 rail shaft, 4 HSR15 blocks, and dustproof plugs. The linear bearing inside ensures the smooth sliding of the blocks on the rail. 5.WIDE APPLICATION - The linear guides help establish a practical and straightforward linear guiding system, widely applied to industrial robots, ultrasonic cleaning equipment, solar auxiliary equipment, etc. ******************************************************************************************************* *Specifications Type: Linear Actuator Feature: Smooth Motion Performance: Little Noise Guarantee: 12 Months Condition: Brand New Bearing Blocks: 4 Pieces Rail Shafts: HSR15, 47.2""/1200 mm Gross Weight: 15 lb/6.8 kg Package Dimensions: 47.6""x3.5""x3.1""/121x9x8 cm ******************************************************************************************************* *Pakcage Content 2 x HSR15-1200 mm Linear Slide Guide Rail 4 x HSR15 Bearing Blocks 1 x Set of Dustproof Plugs