This is the OS SPEED B21 ONGARO EDITION  WITH TB02 COMPLETE SET. It includes the TB02(As known as T-2090) EFRA 2089 tuned silencer and the exhaust system of the / MB01-75 (75mm) manifold.

Displacement:3.49cc / 0.213 cu.in.
Bore:16.27mm / 0.641 in.
Stroke:16.80mm / 0.661 in.
Output:2.68 ps / 2.64 hp / 34,000 r.p.m.
Practical rpm range: 4,000-42,000 r.p.m.
Weight: 352g / 12.42 oz
Standard accessories
Glow plug T-P3
Reducer 5.8, φ6.3
Exhaust seal ring
Dust cap set (3, 16, 18)

Features:

Based on the latest off-road engine O.S. SPEED B2104, the crankshaft has been changed to a counter web shape and use of single tungsten weight crankshaft specially made for this engine to suit his driving style.
The outer head adopts a standard round type, and the laser marking of ONGARO's original logo mark creates a racing atmosphere.
A new size 5.8mm / 6.3mm black anodized restrictor is also used for the carburetor to create an "Engine that can win big races" that matches his requirements.