The correct bleed block sets your caliper pistons at the perfect starting point, which ensures the correct amount of fluid is in your brake system.
If the brakes are bled without a bleed block, you may unintentionally over-fill the system, which can lead to decreased power and/or the pads consistently rubbing the rotor.
Bleed blocks are included in our complete bleed kits: Spare Parts Catalog - Bleed Kits / Tools / Brake fluid / Grease.
You can find a list of Bleed Blocks and Pad Spacers for your specific model in our Brake Bleed Manual. The Universal Bleed Block (part number 11.5018.059.002) can be adapted to most SRAM caliper models: Brake Bleed Manual - Universal Bleed Block.