The Siamp Optima 49 Dual Flush Valve delivers flexible installation capability across plastic and ceramic cistern configurations. Engineered for lid holes ranging from 16mm to 50mm, the system adapts with or without collar depending on diameter requirements. The dual flush mechanism features adjustable small flush volumes from 2 litres to 4.5 litres, providing water efficiency without compromising performance. An actuation effort below 20N ensures accessible operation, while button off-center positioning allows ±15mm flexibility. The adjustable stirrup operates in 12mm increments, and the overflow can be cut in 4mm increments for precise height customisation. A high flush rate of 3.5 litres per second ensures effective waste clearance, while the supplied foam pan seal compensates for pan irregularity. Features & Benefits: Compatible with plastic and ceramic cisterns for flexible installation. Dual flush operation with adjustable small flush from 2 litres to 4.5 litres for water efficiency. Accommodates lid holes from 16mm to 50mm with optional collar configuration. High flush rate of 3.5 litres per second for effective waste clearance. Actuation effort below 20N for easy operation. Adjustable stirrup in 12mm increments and overflow cutting in 4mm increments. Button off-center positioning: ±15mm. Adjustable deadwater level for optimised performance. Includes: foam pan seal for compensating pan irregularity.