The Deep Series Trench Drain End Caps, Coupling Converter and Bottom multi-pipe adapter are an important addition to any custom modular trench drain system. The convertor is not required to connect lengths together. The Polymer converter can be used to connect the end cap to the male-end fitting of the trench drain system. When cutting trench drain lengths along any of the grooved sections at 8 in. intervals at the bottom of the channel, the converter piece can be used to reattach the remaining cut pieces of trench drain lengths: simply clip the convertor to the 2 male-end fittings of the trench drain. The convertor is also used to connect the Deep Series 90º corner SKU# 83330 which has all male-end fittings. When the end cap is installed in reverse, it becomes an adapter piece with a 3 in. cutout section that can be cut out with a hole saw to add a 3 in. drainage pipe to the end of your trench drain system. The bottom pipe adapter connects to the inner cut-able knockout section at the bottom of the trench drain, or to the inner cut-able knockout section of the slim pit. This adapter connects to 3 in. & 4 in. Sch 40, ABS & 4 in. Solid or perforated pipes. Color: Black.