scalloped shell

(multiple of 10 sts plus 1)
Double yo Insert RH needle into next st wrapping yarn around needle twice, complete knit st.

Row 1 (RS) Knit.
Row 2 Purl.
Rows 3 and 4 Knit.
Row 5 *K1, [yo, k1] twice, [double yo] 5 times, [k1, yo] twice; rep from *, end k1.
Row 6 *K5, wyif sl 5 purlwise (dropping extra yo), k4; rep from *, end k1.
Row 7 *K5, wyib sl 5 purlwise, k4; rep from *, end k1.
Row 8 *P5, p5tog, p4; rep from *, end k1.
Rep rows 1-8.