This invention relates to a restrictive seal of the labyrinth type of reduced external size. The invention has an inner deflector which is capable of retaining the lubricating oil within the bearing housing with great efficiency, and a highly accurate system for adjusting and aligning the elements of the labyrinths, ensuring an infinite service life. Because it has very much smaller external dimensions it can be applied as a replacement to the lip seals commonly in use without causing problems to accessory equipment connected to a pump.