ROB-BLS is one of R.O.B.'s karts in Mario Kart DS, the others being the Standard RB and ROB-LGS.
It resembles R.O.B.'s block set used in Stack-Up, and can use it from the start. It has the highest top speed along with the Hurricane, average acceleration, high handling (which is a unique trait for a heavyweight character), but has extremely low drift, and a low Item stat. Also this is one of the best karts for snaking. This kart is very popular due to its top speed, and unique stat, so that is why world record beaters in Mario Kart DS always use this kart for beating world records. R.O.B. uses this kart as the staff ghost for Rainbow Road.