What does this adapter connect?

It joins a 3 x 4 in downspout to a 4 in hub connection. Both ends are sized for standard PVC drainage fittings.

It is a glue-in PVC fitting. Clean the surfaces and join it with PVC solvent cement, the same way as other PVC drainage parts.

Will it fit a metal downspout?

No. It is made for PVC systems. Metal or vinyl downspouts need a different adapter or a transition fitting.

No. It is the adapter alone, so you supply the solvent cement and any fasteners your run needs.

No. This one steps to a 4 in hub connection. Check the outlet size of your fitting before buying.

At Shell Lumber and Hardware, for $5.53, 36% under what the other stores charge, as of our latest check.

14 stores we checked sell it, including Shell Lumber and Hardware, Amazon, Do it Best, True Value, Carr Hardware.

$5.53at Shell Lumber and HardwareChecked 1 h ago

36% under what the other stores charge

Compared across 14 stores. Prices are checked against each store and labelled with when.

It checks today's price at every store, compares the alternatives and answers in about a minute.