The Cleansweep Eleven, manufactured by the Cleansweep Broom Company, was released in 1995, making it the latest broomstick in the series.
Ron Weasley received one as a reward upon being made a Prefect (OP9) and was very happy about it. He tried out for and became a Keeper on the Gryffindor Quidditch Team flying a Cleansweep 11 (OP11, OP13, OP19, HBP11).
Specifications
The Cleansweep Eleven can go from nought to seventy in ten seconds (OP9). This is presumably in miles per hour, as broomstick speeds are typically expressed that way (QA9).
The handle is made of Spanish oak (OP9). Note that oak is a wand wood (PS5).
It features anti-jinx varnish and in-built vibration control (OP9).
Commentary
Notes
Lexicon list of Broom Manufacturers
From the Web
Pottermore features:
Harry Potter Wiki:
Pensieve (Comments)
Tags: celebrations fast flying happy improvement rewards sports surprise wand wood wood