A merge element combines two, concurrent, handshake streams. For every request received from a client, a merge element may send a request to its parent, and for each acknowledgement received from its parent, the merge element may send an acknowledgement to a client. We show that that a merge-element can provide bounded time response if its parent also has bounded time response. We present two new implementations of a merge: one that uses an arbiter, and one that uses Schmitt triggers but no arbiters. Based on these designs, we explore a class of concurrent computations that can be performed in guaranteed bounded time, and we raise some new questions about what is possible in asynchronous design.