Many drivers may not be aware of the significant slack present in their vehicle's factory subframe, which arises because OEM engineers often need to balance performance with factors like comfort, cost, or ease of assembly. For instance, the subframe mounting holes in the 11th Gen Civic are 2mm larger than the bolts, allowing for shifts, vibrations, and rattles during intense cornering or braking. This can reduce steering sharpness and responsiveness. At PRL, WE PRIORITIZE PERFORMANCE, which is why we developed the SRS collar kit to eliminate this slack. 

The PRL Motorsport SRS Collar Kit effectively counters these issues by precisely filling the 2mm gap around the subframe mounting bolts, ensuring a snug fit that prevents any extraneous movement. This adjustment significantly cuts down on vibrations, boosts handling, and increases chassis rigidity, making it ideal for track days, autocross, or simply enhancing everyday driving. Constructed from durable 6061 aluminum and anodized black, these collars ensure lasting performance and reliability. 

Features and Benefits

• Precisely machined to fill the 2mm gap in the subframe mounting bolts, reducing slack and unwanted movement
• Helps to reduce vibrations during hard cornering or braking
• Improves overall handling and increases chassis rigidity
• Ideal for setting up your car for track, autocross, or optimal everyday driving
• Made from durable and long-lasting 6061 aluminum and anodized black

https://www.cj-motor.com/assets/files/PRL-HC11-SRS_INSTALL_V1_1(1).pdf