The perfect infuser does exist. Ideal for cup and teapot alike, this stainless steel infuser is is ideal for all types of tea. The infuser holes are small enough to strain rooibos yet the infusion chamber is large enough to allow your oolong teas to breathe, expand and infuse properly. Comes with a convenient lid that double as a stand for in between infusions. 
 
Dimensions: 2.5" height, 2" diameter