Professional quality laser instrument for fast and accurate measurement of rotational speed with or without contact. Will also measure total revolutions frequency surface speed and distance. 10 Selectable data set memories each with maximum minimum and average or single value reading as appropriate. Supplied with reflective tape for non-contact measurement and three heads for contact measurement. Powered by 9V battery (supplied) and has jack socket for 6V DC supply.Digital Tachometer - Contact/Non-Contact• Professional quality laser instrument for fast and accurate measurement of rotational speed with or without contact.• Also measures total revolutions frequency surface speed and distance.• 10 Selectable data set memories.• Supplied with reflective tape for non-contact measurement and three heads for contact measurement.• Powered by 9V battery (supplied) or 6V DC auxiliary transformer (not included).• Model No. TA050Model No: TA050:Brand: Sealey:Nett Weight: 0.26kg:Measures: Range/Units:Rotation Speed - Contact: 2-20PTDSEATA050