This is what ESP say about the B-204SM Fretless Bass:
With its unique coloration and grain pattern highlights, spalted maple is a great look for a bass that stands out from the crowd. The B-204SM FL is an excellent choice in an affordable fretless bass that includes an ash body with a spalted maple top in Natural Satin finish, along with a thin U-shaped 5-piece maple/jatoba neck for excellent playing feel, and 24 clearly marked fret indicators to quickly hit the pitch you want. You also get passive ESP Designed SB-4 pickups, along with an active ABQ-3 EQ, and good-looking black nickel hardware. Available in Natural Satin finish.