Powdered Bronze Bearing
The size is nearly the same LMS8UU Linear Bearing a short body linear bearing for 8mm smooth rod.
ID10*OD16*L15 is availble in stock at same price 0.55USD/pc.
Ultimaker Bushing ID8*OD11*L22
Oil-impregnated self-lubricating sleeve bearing made from bronze by blending powders. Bearings of this type offer the performance and maintenance-free characteristics needed for applications.
This sleeve bearing is applied in Ultimaker working with 8mm Smooth Rod. You could try this self-lubrication sleeve bearing to replace a LM8UU Linear Bearing.
Much shorter and longer self-lubricating bearing are available on request.