The TDC (Top Down Center) carriage is designed so that the Hop-Up Maxx cameras incorporate the use of M-nubs that work perfectly with ER-Hop (elongated R-Hop heads, typically 6 mm long for long distance shooting. ). The longer patch would achieve an improvement in accuracy and consistency, generally for DMR snipers. The M-nub ensures an evenly distributed force applied to the R-Hop head. This, in turn, ensures that the head can maximize its application on the ball to obtain the most stable and uniform spin for the much desired R-hop performance. Works with Flat-hop and Maple Leaf Super Macaron MR-Hops. Features: · Modifications to the side slider bars compared to the original: This ensures a tighter fit on the chamber to achieve absolute top-down force thrust in the center of the R-hop head while avoiding any tipping · The overall contact area has been expanded to 6mm to cover the majority of the Hop-up windows. This ensures that all areas of the ER-hop patch are pushed down equally. Also, this covers more of the chamber window for a better air seal · 3M adhesive incorporated into the back of the M-Nub for optimal contact with the trolley base: this is a strong bond, however.