21° 3-1/2 in. Round-Head Framing Nailer and 15° 1-3/4 in. Coil Roofing NailerRIDGID introduces the 21 3 1 2 in. Round Head Framing Nailer and 15 1 3 4 in. Coil Roofing Nailer. The round head framing nailer is constructed of magnesium metal housing and is the fastest in in its class at eight nails per second compared to competitors' three nails per second. The coil roofing nailer s a perfect combination of power, weight and speed. Packed with Fasten Edge Technology, an industry leading feature set, this nailer can take on any