This is a BLADE BLHA1006 20A ESC BLHeli Opto Quad Pack. Features: 4 Pack of Thrust ESCs, Pre-Flashed with BLHeli, Active Dampening and One Shot activated, 20A Continuous with 25A (10sec)burst, Failsafe protection, over-heat protection and low voltage cutoff, 2-4s battery, Opto (no bec), Only 6.8g each, Signal Frequency: 20-500Hz, PWM Frequency: 18KHz, Size: 24.5 x 12.9 x 5.2mm. Manufacturer: Blade. Model Number: A1006. MSRP: 79.39. Category 1: Control & Electrical - RC. Category 2: Control. Availability: Ships in 5 to 10 Business Days. Trainz Product Id: 12194911.