The H303 is a 7% H unknown composite motor from Contrail.
| Average Thrust: | 286.0610 N | 
| Certified By: | Tripoli Rocketry Association | 
| Class: | 7% H | 
| Delays: | 1000 seconds | 
| Diameter: | 38.0000 mm | 
| Length: | 508.0000 mm | 
| Letter: | H | 
| Manufacturer: | Contrail | 
| Name: | H303 | 
| Peak Thrust: | 780.1500 N | 
| Propellant: | APCP | 
| Status: | In-Production | 
| Thrust Duration: | 0.6000 s | 
| Total Impulse: | 171.6370 Ns | 
| Total Weight: | 589.0000 g | 
| Type: | Unknown | 
![]()  | 
              ![]()  |