This is the A10-0T Booster Stage Model Rocket Engines/Motors from Estes.
Suitable for Ages 10 & Older with Adult Supervision for Those Under 12.
Four A10-0T Engines
Four Igniter Plugs
Booster stage engine
Has to be used with a mini engine
Engine is for flights in rockets weighing less than 4 ounces,
including the engines
Engines tested and certified by the NAR
Easy to use and comes with clear instructions
Length: 1.75" (4.4cm)
Diameter: .5" (13mm)
Adult Supervision for Children Under 12