A reduction of the number of parts and the prevention of a gap and a difference in level from occurring in the passage route of the rollers. A slider S is provided with a pair of guide holes 31, 32 for forming a return guide path. Guide cylinders 34 in which the rollers 37 roll are inserted in the guide holes 31, 32. A pair of passage groove 42, 43 having different depth and intersecting with each other is provided in each of the end caps e1, e2. A divider frame 36 is provided integrally with one end of each guide cylinder 34 for defining the intersecting passage grooves. The divider frame 36 is inserted in a cross portion of the intersecting passage grooves, whereby the outward guide path and the return guide path are defined while still intersecting.