Yellow day time smoke grenades by Klasek Fireworks.

This 5 pack smoke grenade produces a thick plume of Yellow smoke for approximately 60 seconds.

Yellow Smoke Grenade Pack Specifications
Carton Quantity: 5 x Yellow Smoke Grenade
Firework Brand: Klasek Fireworks 
Approx Duration: 60 Sec
Product Weight: 723g
NEC (Net Explosive Content): 225g
Firework Pack Dimensions: 20cm x 31cm
Noise Rating: 0/10
Classification: 1.4G
Safety Distance: Outdoor use only