The H121 is a 43% H unknown composite motor from Contrail.
| Average Thrust: | 123.8550 N | 
| Certified By: | Tripoli Rocketry Association | 
| Class: | 43% H | 
| Delays: | 1000 seconds | 
| Diameter: | 38.0000 mm | 
| Length: | 516.0000 mm | 
| Letter: | H | 
| Manufacturer: | Contrail | 
| Name: | H121 | 
| Peak Thrust: | 265.5140 N | 
| Propellant: | APCP | 
| Status: | In-Production | 
| Thrust Duration: | 1.8500 s | 
| Total Impulse: | 229.1320 Ns | 
| Total Weight: | 612.0000 g | 
| Type: | Unknown | 
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