the C5 is:

Size: .21
HP (bhp): Not Available
Bore: 16.22 mm
Stroke: 16.8 mm
Ports: 5
Weight: 365 g
Crank: SG
Construction: ABC
Displacement: 3.49 cc
Type: Off-Road
Exhaust: Rear
Carb: Slide
RPM Range: Not Available
Webpage: www.rbproducts.com
Est. Street Cost: Not Available
Average Rating: 5 out of 5

the S5:

Size: .21
HP (bhp): Not Available
Bore: 16.42
Stroke: 16.42
Ports: 5
Weight: 356
Crank: SG
Construction: ABC
Displacement: 3.49cc
Type: Off-Road
Exhaust: Side
Carb: Slide
RPM Range: Not Available
Webpage: www.rbproducts.com
Est. Street Cost: 200
Average Rating: 5 out of 5

I made a mistake, I have the CS not the C5, still like it.

Dan.