The answer is ARF's. A very small percentage of hobbyist truly build anymore, so I guess Horizon Hobbies decided to NOT keep in stock what doesn't sell. If you didn't know, Horizon Hobbies bought Hobbico, Tower's Parent company. If you ever noticed, HH never really had true kits to build. Just ARF's. It doesn't make sense to keep inventory that rarely sells. Builder's kits are going away just as glow engines are going away. Technology moves forward.