These are THK HSR Series, 8mm wide, Miniature, Linear Motion Bearings.
These bearings are used - Like New condition - with 30 day Warranty.
Actual picture of block and rail.
For other bearing supplies see:
www.kkdepot.com/category.asp?cat=11
Price $15.00 each (2 available 15mm rail length with one block)
Price $20.00 each (1 available 75mm rail length with one block)