This block can be used as a joining component or as an end cap. It compliments the Massive Crown E-Vent moulding profile. The joining block aids you in creating the beautifully finished exterior crown mouldings that you envision. The E-Vent system provides a beautiful means to roof ventilation, as it extends the life of the roof and enriches the exterior with unmatched style. The joining block/end cap is precision molded in urethane. Those in search of a traditionally beautiful and durable trim material can find favor with the high performance qualities of urethane. Urethane trim is non-porous and it does not warp, crack or rot. Urethane trim is also pre-primed.