Around 2015 and 2017, some manufacturers(namely Samsung and LG Electronics) offered washers and dryers that either have a top loading washer and dryer built on top of a front loading washer and dryer respectively (in Samsung washers and dryers) or offer users an optional top loading washer that can be installed under a washer or dryer (for LG washers and dryers) Both manufacturers have also introduced front loading washers allowing users to add items after a wash cycle has started, and Samsung has also introduced top loading washers with a built in sink and a detergent dispenser that claims to leave no residue on the dispenser itself. In IFA 2017, Samsung released the QDrive, a front loading washer similar to the Dyson ContraRotator but instead of 2 counterrotating drums, the QDrive has a single drum with a counterrotating impeller mounted on the back of the drum. Samsung claims this technique reduces cycle times by half and energy consumption by 20%.