Lewmar 29925031BK 50MM Fiddle Block, Black, 1/4" 3/8" Line EPAOILPB3 Probably the most relevant is

Probably the most relevant is the ability to shut the pump off as soon as it senses it is running dry

eliminating the need to create perfect cut-outs (like with the Color Control GX)

which is known to the State of California to cause cancer

Replaces old item number SM8007

Lewmar 29925031BK 50MM Fiddle Block, Black, 1/4" 3/8" Line EPAOILPB3 Probably the most relevant isSynchro block are engineered for speed, efficiency and superior handling. High density, free spin plain bearing and self aligning head reduce friction and increase efficiency. Easy to use, patented shackle post lock. Stainless steel straps and glass fibre reinforced cheeks. Sheave bearing pin & line size for optimum efficiency. Black.