The Zius BK1s is a lightweight Automatic Electric Blaster (AEB). Featuring the same logic board as the BK2s, but with a longer barrel, this blaster is capable of slightly higher average FPS. Available in bright yellow. We initially carried the BK2s, but the factory has since simplified production to offer only the BK1s. *NOTE: The recommended age for this blaster is for adults 18+. Teens 14+ may only use this blaster with appropriate adult supervision. Use the BK1s AEB at your own risk.  FEATURES:• Injection-molded super-stock AEB• Select fire (Safe/Semi/Full-Auto) • Removeable 1.6 x 155mm spring• Removeable 200mm barrel• Buffer Tube battery stock• T238 DTU control board• Built-in low-voltage cutoff and jam detection! INCLUDES:• 1 BK1s Blaster in Yellow color• 1 12-Round Zius Magazine (not talon-compatible)• 2 M-Lok Picatinny Plate Attachments• 12 Worker HE Short Darts Battery, charger, and LiPo alarm are sold separately! See the links below for our recommendations! PERFORMANCE:Average FPS (Standard Deviation)• 172 (6) FPS on 3SAverage Rate of Fire• 6 RPS in Full-auto mode on 3S SPECS:• Material: Nylon, ABS + aluminum• Dimensions:• Weight: • SKU:  LINKS:• Recommended 3S Battery• Recommended Darts• Magazines• More AEBs