Silicone Cupcake Muffin Baking Cups Liners 36 Pack Reusable Non-Stick Cake Molds Sets

What size are the square cups and the rectangle cups?

Can these be used by themselves in a convection oven?

Can I use these cups for egg muffins?

do you need to use a muffin tin? will they spread w/o muffin tin when batter expands? THX