12 x 960ml Proshot BLUE Cassette Toilet Fluid. This biodegradable toilet chemical quickly dissolves waste, eliminates odours and leaves behind a long-lasting, fresh fragrance. It's formaldehyde free and has easy rinse non-staining dyes making it safe for septic tanks. 60ml per 10L (16 doses per bottle) 12 bottles per box. Size: 960ml.