The Middle Bulkhead for the Wilderness Systems Tempest 170 is designed to fit the Wilderness Systems Tempest 170 Roto but may need to be cut to fit.
Purchase of a replacement middle foam bulkhead for my plastic Tempest 170 was made necessary after a bear, known locally as "the chewer", decided to verify the emptiness of my day hatch by pawing through the bulkhead rather than just looking into the hatch opening. (Always leave the hatch covers off in bear country.) I should be thankful that he was careful not to damage the seat back, but he lost all credibility after chewing and clawing several other non-food items, including a white gas bottle, two paddle floats, a pump, two empty dry bags, a deck bag, and my two day old map. Anyway, the bulkhead arrived from harmonygear within a couple of days, the fit was fine after removing the old marine adhesive, and I am now forewarned about north Oak (site 6) in the Apostles. My only small criticism of the bulkhead is that the tape covering several small, pre-installed patches of adhesive around the rim were too short to reach with a needle-nose after the bulkhead was in place, rendering them pointless. You will use marine sealant along the edges on both sides to complete the waterproof installation, anyway, so the manufacturer should either lengthen the tape or just do away with them entirely. Just so you know, the entire installation, including cleaning out the old bulkhead and fitting and sealing the new took about an hour, with another two for drying. Good luck.