2" slip is designed to slip over pipe with 2" inside dimension or 2" spigot.
2" spigot is the same dimensions as pipe with 2" inside dimension. Fits into 2" slip.
2 - 3/4" Smooth Barbed Ports are designed to fit inside 3/4" clear tubing or flex pipe
Manifold must be glued into place
For maximum effectiveness, it is strongly recommended to attach the tubing to smooth barbed ports using glue, and use clamps to secure it in place when clear tubing is being used. If using flex pipe clamps are not necessary.
Unneeded ports can be plugged with 3/4" new style manifold plug, sold separately.