82224001. This DORMAKABA BTS80 EMB Floor Spring features an electro-magnetic hold open with fully controlled closing and adjustable speed. It has adjustable latching action and mechanical backcheck and can be used on fire and smoke check doors. It is suitable for both single and double action applications.. Floor spring with electromagnetic hold-open. Can be used on fire and smoke check doors. Suitable for both single and double action applications. Adjustable latching action