Rocket Engine Specifications: Diameter Length Total Impulse Propellant Weight Motor Weight Delay Seconds Propellant Type Fits Estes Mount 13 mm 1.75" 2.50 N-sec 3.70 g 6.7 g Plugged B Mini Estes-1505 Retail: $8.99 Our Price: Learn about Payment Options | Security | Privacy | Shipping | Our Company. Trademarks property of Centuri Corporation, Custom Rockets, and ToyBiz Inc.